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J Tiers
09-03-2011, 03:19 PM
S10, 2000, 2.2l, 4.10 rear end, clutch vehicle.

1)
Brake pedal soft, take it is.

Rear brake drum problem, seems fixed.

30 days later (4 days ago), pedal INTERMITTENTLY going to floor when foot is on brakes at stoplight. Brakes feel odd much of the time. After pedal goes to floor, let up and pedal "catches" again and goes slowly to floor again, with that "squirmy" feel that is typical. Works fine sometimes.

Take in, shop cannot find a darn thing wrong. They think everything is fine.

I insist that is does what I have had happen. They say they can replace master cylinder for $300, but can't guarantee a fix. They don't think it is the proportioning valve because "they 99.999% leak when bad".

2)
clutch needs replaced at 127K.

Same shop replaces clutch also, same time. Clutch has concentric hydraulic cylinder, they replace that, too, since otherwise it's pull the tranny again later. Clutch working fine, but starting to squeak, 127k is enough for any clutch.

I pick it up. All OK.

Next day, while driving to ohio, shifter will not move. Pump clutch and it releases, clutch pedal must be on floor into the rubber mat to release. Fluid reservoir is "slurping" when clutch is released.

In Ohio, I have the system bled, and all is OK.

About 30 days later (now) clutch INTERMITTENTLY is back to the "on the floor" biz, with hard shifting. But it will "switch back" to working fine in a matter of 3 blocks driving, then revert to "on the floor" again.

have not taken it back for that yet, I figure they can't find anything wrong with THAT either.

I paid 'em "some $$" for their work, and I want it fixed.

Are they as clueless as it seems, or what?

Black_Moons
09-03-2011, 03:30 PM
Hows the fluid levels? I don't know much about cars, but it seems to me both those problems could be low fluid level letting air into the system, maybe only happening when its on a hill (or only 'fixing' itself when on a hill)

Air in the system would also displace a little fluid, so you might end up with 'normal' fluid levels when there is air in the system, but low levels when its 'acting correctly'

Consider just toping it up to the max acceptable levels? Its a cheap and easy fix to try.

I also seem to recall brake fluids tend to be rather incompatable with eachother if someone refilled it recently without checking/using the exact right type.. And then theres brake fluid boiling and such.. Sure your brakes and/or clutch isent draging? Maybe check the clutch tempature if you can get at it, after idling in gear with the clutch in for awhile.. Alternatively it might not be fully engaging and sliping a little. That'd likey show up when going up a steep hill or accelerating.

And check brake tempature after driving around without using them much.

winchman
09-03-2011, 03:56 PM
The concentric slave cylinder may be one of the all-time bad ideas in the automotive world. It's a collusion of the bean counters and the weight-reduction guys. It's a pi$$-poor design installed in the worst possible environment. It seems every vehicle they're installed on has trouble with them.

Thank goodness for automatic transmissions.

JCHannum
09-03-2011, 04:21 PM
Ditto on the problems with the slave cylinder. I had one on a Ford P/U. Final solution was replacement with a GM P/U with auto transmission.

Scottike
09-03-2011, 04:37 PM
I also seem to recall brake fluids tend to be rather incompatable with eachother if someone refilled it recently without checking/using the exact right type...

Black Moons is right, DOT 3 & DOT 5 brake fluids are incompatable - If the two get intermixed they turn into a jelly kind of goo that can cause the kind of symptoms your talking about and worse.
Dot 5 is colored (purple is what I've seen) Dot 3 is clear/amber. The cap on the master cyl. should say what's called for.
Check the color in the reservoir.

Arcane
09-03-2011, 06:05 PM
Years ago I had a 1980 Chevy 4X4 that the brake pedal started to go to the floor. Fortunately it only happened when I came to a stop, never when actually driving. After the second time it did this, I bought a replacement master brake cylinder and swapped them out and being a curious fellow back then, I pulled it apart to have a look inside and sure enough, the rubber lip seal on the piston was worn thin on the bottom side, thin enough that it could fold over on itself and bypass fluid.

Your brake problem might be the very same thing as mine was and a new master cylinder might be the only cure. As I recall, an aftermarket one was identical in every way to the OEM and considerably cheaper and worked flawlessly until I parked the truck.

Don Young
09-03-2011, 11:02 PM
'Any' time a brake pedal goes to the floor after being bled and working properly the fluid is escaping from the pressure side of the seal/piston. If the fluid is not leaking from a wheel cylinder or line, it is passing the seal/piston in the master cylinder. This indicates a defective master cylinder, whether or not it has been rebuilt or replaced with a new one. It is not too uncommon to get a bad one (or more) out of the box.

Mike Folks
09-03-2011, 11:48 PM
DOT 3 VS DOT 4 Brake Fluid

I just flushed my brake lines with new DOT 3 fluid only to find out that the master cylinder has a leak. Instead of rebuilding the master cylinder, I bought a 'newer' used MC off of ebay, but it calls for DOT 4 instead of DOT 3! D'oh! Well, I've heard that 3 & 4 are very similar and I'm wondering how thoroughly I need to flush the DOT 3 fluid out of the brake lines? Can I just 'push' the DOT 3 fluid out by adding DOT 4 to the master cylinder and pump until I think I have all of the DOT 3 out of the lines? How would you do it?

...Can I just 'push' the DOT 3 fluid out by adding DOT 4 to the master cylinder and pump until I think I have all of the DOT 3 out of the lines? How would you do it?

YES. That method is just fine. Same for the routine "flushes" without requiring re-bleeding from scratch.

I use a rubber squeeze syringe to remove most of the existing reservoir fluid, but leaving the bottom ports covered with fluid so as to avoid air entering the line. Then fill with new fresh fluid, pump it through (always leaving the bottom ports covered with fluid so as to avoid air entering the line) and repeat refilling and pumping until the new fresh fluid exits the bleeder valve.

Brake Fluid Problems

"I like to go with DOT 5 fluid when I rebuild the brakes, just a better product"/quote]

Maybe not better, but certainly different. An alarm went off in my brain, so I Googled this up.

"More than you ever wanted to know about brake fluid....

Brake fluid facts

By Steve Wall
As a former materials engineering supervisor at a major automotive brake system supplier, I feel both qualified and obligated to inject some material science facts into the murky debate about DOT 5 verses DOT 3-4 brake fluids. The important technical issues governing the use of a particular specification brake fluid are as follows:

Fluid compatibility with the brake system rubber, plastic and metal components.

Water absorption and corrosion.
* Fluid boiling point and other physical.
* Brake system contamination and sludging.

Additionally, some technical comments will be made about the new brake fluid formulations appearing on the scene.

First of all, it's important to understand the chemical nature of brake fluid. DOT 3 brake fluids are mixtures of glycols and glycol ethers. DOT4 contains borate esters in addition to what is contained in DOT 3. These brake fluids are somewhat similar to automotive anti-freeze (ethylene glycol) and are not, as Dr. Curve implies, a petroleum fluid. DOT 5 is silicone chemistry .



Fluid Compatibility
Brake system materials must be compatible with the system fluid. Compatibility is determined by chemistry, and no amount of advertising, wishful thinking or rationalizing can change the science of chemical compatibility. Both DOT 3-4 and DOT 5 fluids are compatible with most brake system materials except in the case some silicone rubber external components, such as caliper piston boots, which are attacked by silicon fluids and greases.

Water absorption and corrosion
The big bugaboo with DOT 3-4 fluids always cited by silicone fluid advocates is water absorption. DOT 3-4 glycol based fluids, just like ethylene glycol antifreezes, are readily miscible with water. Long term brake system water content tends to reach a maximum of about 3%, which is readily handled by the corrosion inhibitors in the brake fluid formulation. Since the inhibitors are gradually depleted as. Since the inhibitors are gradually depleted as they do their job, glycol brake fluid, just like anti-freeze, needs to be changed periodically. DOT 5 fluids, not being water miscible, must rely on the silicone (with some corrosion inhibitors) as a barrier film to control corrosion. Water is not absorbed by silicone as in the case of DOT 3-4 fluids, and will remain as a separate globule sinking to the lowest point in the brake system, since it is more dense.

Fluid boiling point
DOT 4 glycol based fluid has a higher boiling point ( 446°F) than DOT 3 ( 446 ºF), and both fluids will exhibit a reduced boiling point as water content increases. DOT 5 in its pure state offers a higher boiling point (500°F) however if water got into the system, and a big globule found its way into a caliper, the water would side at temperatures very much below freezing, let alone at 40° below zero, silicone's low temperature advantage won't be apparent. Neither fluids will reduce stopping distances.

With the advent of ABS systems, the limitations of existing brake fluids have been recognized and the brake fluid manufacturers have been working on formulations with enhanced properties. However, the chosen direction has not been silicone. The only major user of silicone is the US Army. It has recently asked the SAE about a procedure for converting from silicon back to DOT 3-4. If they ever decide to switch, silicone brake fluid will go the way of leaded gas.

Brake system contamination
The single most common brake system failure caused by a contaminant is swelling of the rubber components (piston seals etc.) due to the introduction of petroleum based products (motor oil, power steering fluid, mineral oil etc.) A small amount is enough to do major damage. Flushing with mineral spirits is enough to cause a complete system failure in a short time. I suspect this is what has happened when some car owners changed to DOT 5 (and then assumed that silicone caused the problem). Flushing with alcohol also causes problems. Older brake systems should be flushed only with DOT 3 or 4.

If silicone is introduced into an older brake system, the silicone will latch unto the sludge generated by gradual component deterioration and create a gelatin like goop which will attract more crud and eventually plug up metering orifices or cause pistons to stick. If you have already changed to DOT 5, don't compound your initial mistake and change back. Silicone is very tenacious stuff and you will never get it all out of your system. Just change the fluid regularly. For those who race using silicone fluid, I recommend that you crack the bleed screws before each racing session to insure that there is no water in the calipers.

New developments
Since DOT 4 fluids were developed, it was recognized that borate ester based fluids offered the potential for boiling points beyond the 446°F requirement, thus came the Super DOT 4 fluids - some covered by the DOT 5.1 designation -which exhibit a minimum dry boiling point of 500°F (same as silicone, but different chemistry).

Additionally, a new fluid type based on silicon ester chemistry (not the same as silicon) has been developed that exhibits a minimum dry boiling point of 590°F. It is miscible with DOT 3-4 fluds but has yet to see commercial usage." I learned in the past thru others mistakes not to switch to DOT 5 in systems designed for DOT 3 or 4.

J Tiers
09-03-2011, 11:53 PM
Yah........

Various random things relatd to the issues.....

The clutch is done fixing itself, I have to pump it now.

If it is leaking, the leak goes into the closed bell housing, and is unlikely to improve clutch performance......

Concentric cylinder seems lie a horrible idea, but the original one worked for 11 years and 127K miles. it wasn't failing when replaced, and maybe I should have had them put it in a box for me.... New one, maybe is not so good........

I now have the brake warning light , AND the ABS warning light on most of the time I drive. Originally, they would only come on if I released the parking brake AFTER starting the engine.... if off first, no lights. Now, both lights most of the time.

This has been a good truck, and I see these apparently clueless batards gros are now apparently messing it up, replacing things that do not need it, and breaking things that were not broken before.

Maybe I am being uncharitable?

bruto
09-04-2011, 12:18 AM
Sounds like master cylinder. It's pretty common for a worn out master cylinder to go to the floor intermittently. One thing you can do to check is to turn on engine, and then push steadily, but not too hard or fast, on the pedal. If it sinks, it's pretty well diagnostic for a bad MC. The cups are designed to expand under pressure, so when you hit the pedal hard or fast, it will usually work fine, but will leak down under lighter pressure.

J Tiers
09-04-2011, 12:36 AM
May be..... it's what I think. I already had them replace the master cylinder...... Now I have brake and ABS lights.....

All I know now is that they "touched" BOTH the brakes and the clutch system.

And now BOTH pedals sink to the floor or are showing "system failure" lights.

So everything they have "touched" is failing.

Scottike
09-04-2011, 01:31 AM
Sounds like master cylinder. It's pretty common for a worn out master cylinder to go to the floor intermittently. One thing you can do to check is to turn on engine, and then push steadily, but not too hard or fast, on the pedal. If it sinks, it's pretty well diagnostic for a bad MC. The cups are designed to expand under pressure, so when you hit the pedal hard or fast, it will usually work fine, but will leak down under lighter pressure.

Yea, but the outfit replaced the clutch too, and now similar problems with that too. Sounds like it's time to shop for a new shop. Sometimes you just have to cut your losses and run.
edit: or find a new shop AND a lawyer.

bruto
09-04-2011, 10:21 AM
Yea, but the outfit replaced the clutch too, and now similar problems with that too. Sounds like it's time to shop for a new shop. Sometimes you just have to cut your losses and run.
edit: or find a new shop AND a lawyer.True enough, but this would also not be the first master cylinder to come out of the box defective. If it's going to the floor and not leaking, it's still the prime suspect.

mike os
09-04-2011, 10:46 AM
cylinder does not have to "leak" to have this problem.. the seals can also pass fluid internally.... net result is the same... goes to floor. in a new unit it was probably damaged when made.

if the brake/clutch fluid reservoir is always full the I would suspect passing seals, if you need to replace/top up fluids then its leaking somewhere... if it is and there is no sign of a leak then the bell housing or vacuum assist chamber is the most likely place for fluid deposition.

given that the abs/brake warning light is on and you have a brake pedal/system problem you really should not be driving this on the public highway.

I think you need a new garage, even a trained monkey aught to be able to sort this kind of fault.

MotorradMike
09-04-2011, 10:48 AM
This has been a good truck, and I see these apparently clueless bastards are now apparently messing it up, replacing things that do not need it, and breaking things that were not broken before.

Maybe I am being uncharitable?


This has been my experience also.
Everything they broke was "weak".

I don't think you're being uncharitable.

J Tiers
09-04-2011, 12:30 PM
The clutch is almost certainly due to needing to be bled...... it's the same symptoms.
The question is, WHY it needs that after it has been bled once already? I haven't looked at fluid level (hey, I PAID to have this dealt with) but that could be the issue...

but, that means there is a leak..... so they messed that up.


The brakes seem to be working, the pedal is no longer going to floor.

But with brakes I get TWO types of system failure light.

I THINK that can be from incomplete bleeding of the system, where the ABS branch was not bled right.

If I have to pay another shop to re-do all the work, I am going to be mad enough to burn down shop #1...... without even lighting a match.

terry_g
09-04-2011, 12:54 PM
My daughter's 92 Chev Corsica was having a similar problem.

I was advised by a mechanic with experience on these systems to unplug the ABS connectors from the actuators.
If the problem went away then it was probably contamination from wearing seals causing something in the anti-lock system to malfunction.

The brakes work perfectly with the connectors removed. The new parts apparently are no longer available to repair it.

When they replaced your master cylinder they may have allowed air to enter the ABS module. There are different procedures to bleed the brakes in
vehicles with ABS. Some require that the proper scanner be connected to operate the pumps to push the fluid through. There may be bleeders on the ABS module.
There will be an order that you have to bleed the bleeders.
The shop that did the job may not have the necessary equipment and training.

Terry

Scottike
09-04-2011, 01:36 PM
True enough, but this would also not be the first master cylinder to come out of the box defective. If it's going to the floor and not leaking, it's still the prime suspect.

I know that defective master cylinders do come out of the box, and so should that shop.
The bottom line is that they don't seem real anxious to stand behind their work, or to thoroughly investigate the OP's complaint.
What are the odds of getting a bad master AND a flakey clutch cylinder in a row, from the same shop?
The more likely sceanario is incorrect/poor installation of both units.

edit: Rebuilt units are especially notorious for being bad out of the box, hence most reputable shops only use new (not neccessairly OEM), unless the customer asks
for rebuilt or new is not available. In either case the customer should be advised that the shop is making the repairs with rebuilt parts rather than new.

aboard_epsilon
09-04-2011, 03:01 PM
DOT 5 is silicone brake fluid..usually purple..non hydroscobic..but you do end up with slighlty softer pedal .. ideally system should be flushed and new seals all round before using it ..fluished with meths ..then blown out..you're better off taking the whole lot apart though.

DOT5 is a long term fluid ..it does not degrade like other fluids, can be left in for many years ..break systems filled with DOT5 will last a lot longer than filled with 3 and 4..no water means no rust and little wear.

The other two, 4 and 3 are compatible with each other ..4 is higher spec than 3 ..higher boiling point.

if master cylinder seals are goosed ..weeks before you will see the clean fluid in the master cylinder turn dirty black colour.

I think the DOT rating is a British scale ..DOT stands for Department of Transport .

All the best.markj

psomero
09-04-2011, 03:29 PM
May be..... it's what I think. I already had them replace the master cylinder...... Now I have brake and ABS lights.....

All I know now is that they "touched" BOTH the brakes and the clutch system.

And now BOTH pedals sink to the floor or are showing "system failure" lights.

So everything they have "touched" is failing.


time to find a new shop, perhaps?

roundrocktom
09-04-2011, 07:24 PM
With Brake Systems:

You really should flush (bleed out fluid) every two years. As pointed out it picks up moisture, causing corrosion. If you do that, hydraulics brake components will last years.

After replacing a clutch pressure plate, it will have a higher clamping force and need a little more pressure to open it. Higher pressure for the hydraulic system, but a marginal master cylinder will start to fail. One solution is to start pumping it, if that helps... time to replace the master cylinder.

Ditto on brakes. When pads are replaced, pistons are pushed back into the caliper housing to make room for new pads. That old fluid, with a bunch of suspended junk gets pushed back up into the master cylinder. Occasionally that is enough to cause problems for the Master or ABS valve.

Most people do not think of brake fluid as a 'replace every so often' item. Engine and Transmission Oil, yes. Brake Fluid tends to get overlooked, but flushing it every few years saves $1000's in the long run.

Back to the shop... Sounds like a decent shop, and just realize this does happen from time to time. I used to deal only with Datsun's and would give folks a heads up as most of the vehicles I was working on were '63 to '73 vintage.

J Tiers
09-04-2011, 11:07 PM
Just to make things interesting........

Drove it out to dinner tonight..... on the "drive it until there is NO QUESTION what's up" theory.

So....... clutch pedal started out on the floor, with the shifter almost locked-out.

3 blocks later, it went back to normal, and was fine the rest of the drive, both ways.

And, NO warning lights.... despite absolutely NOTHING having been done to it.

(last night they were on solidly the whole time we were out)



After replacing a clutch pressure plate, it will have a higher clamping force and need a little more pressure to open it. Higher pressure for the hydraulic system, but a marginal master cylinder will start to fail. One solution is to start pumping it, if that helps... time to replace the master cylinder.


it was locking the shifter, "slurping" in the reservoir, and needed pumped to work the day after the clutch was replaced, BUT flushing the system and bleeding it correctly made it work for 30 days. I still have not looked to see if there is low fluid in the reservoir, though.




Ditto on brakes. When pads are replaced, pistons are pushed back into the caliper housing to make room for new pads. That old fluid, with a bunch of suspended junk gets pushed back up into the master cylinder. Occasionally that is enough to cause problems for the Master or ABS valve.


The ORIGINAL problem was soft brakes..... they first replaced the rear pads. That didn't cure it, after 30 days it was back to "normal" soft brakes, progressing to *intermittent* pedal-to-floor action.

I had them replace master cylinder (apparently they are no longer "re-built"), and brakes are good now..........But the brake and ABS lights are on much of the time.... this is new after the work was done.

Mike Burdick
09-05-2011, 12:20 AM
I vote for the "clueless shop". ABS brakes are quite complicated and need a knowledgeable mechanic to work on them.

For those that are not familiar with ABS brakes, here's some information...

http://autorepair.about.com/od/glossary/a/def_ABS.htm

J. Randall
09-05-2011, 12:35 AM
If your clutch reservoir turns out to be full when you check it, then the slave cylinder is bypassing at times and should be replaced again. On your warning light problem, some proportioning valves have a little piston in them that has to stay centered to keep the lights off. Could be that it is not truly centered at all times, and is causing the problem, if it was mine I would check the back brake shoes and see if maybe they need to be adjusted out a little more, a little extra travel there can cause the piston to off center and the light will come on.
James

J Tiers
09-05-2011, 01:22 AM
Don't get me started on ABS.......... it works on ice, everywhere else it is a HAZARD.

That link has the standard explanation of ABS.... Don't believe it.... it's largely BS. Dangerous BS.

The FACTS of the ABS are that it appears to simply inhibit ALL braking for about 1 second on the affected wheels.... This may not be true if you are on ice, but it is true for those cases (very very common) where the ABS falsely triggers on dry pavement.

With the S10, on dry pavement, if the wheel hits a bump the size of a "piece of parakeet poop" (i.e. not much) while braking, the affected circuit SHUTS OFF for 1 second+, and the truck will VIOLENTLY slew to the side, requiring quick reflexes to avoid slewing sideways into traffic in the next lane..

Sure, sure, I hear the buzzing, and feel something in the pedal , but the EFFECT is that braking ceases for a count of 1 to 1.5 seconds, either on once circuit, or on both.

If the ABS truly worked the way it is advertised to, as soon as the wheel had got over the bump that set the ABS off, relative motion would be normal, and ABS action would cease....

Reality is that it takes 1 to 1.5 sec REGARDLESS OF CONDITIONS.

At the same time, braking is VERY degraded..... I have, with foot solidly on the brake, rolled virtually unbraked out into the middle of intersections.

There is , according to two different dealers, NOTHING WRONG with the ABS, it is "perfect"....... Perfectly awful, perhaps, but IMO hardly "perfect".

I wouldn't know or care if the ABS was not working up to par..... it might be better if it failed, for the 99% of times that the ABS "goes off" on dry pavement vs 1% or less that it has ever gone off while on ice.

I'd pull the fuse for it, except for the fact that any lawyer would make everything my fault in case of an accident just on that basis alone, no matter WHO was really at fault.

I don't care if the ABS is shut off, I just want the warning lights to be off, and the brake pedal and clutch to work right..... CONSISTENTLY, so I can say truthfully that I know of nothing wrong with the vehicle.

Joe Rogers
09-05-2011, 11:37 AM
You are going to have to find a shop that can diagnose and repair your truck. It isn't the shop that has worked on it so far. The clutch needs a clutch master cylinder. The slave cylinder won't bypass without leaking externally. The brake light on in conjunction with the abs light is a base brake system problem. Not an abs problem. Any time the red brake warning light is on due to a pressure imbalance issue it will also trip the abs light as the abs senses the fault and defaults off.
Joe

Scottike
09-05-2011, 12:02 PM
I had them replace master cylinder (apparently they are no longer "re-built)

I'm sure anyone with an older vehicle that new parts are no longer available for will be very dissappointed to hear that.

Where did you hear that?

I just called my favorite parts house and they have rebuilt/remanufactured available for any of the common makes & models

J Tiers
09-05-2011, 02:33 PM
I'm sure anyone with an older vehicle that new parts are no longer available for will be very dissappointed to hear that.

Where did you hear that?

I just called my favorite parts house and they have rebuilt/remanufactured available for any of the common makes & models

Sigh........

Used to be, the shop would get a rebuild kit.

Now they replace the unit.

Dat bettah?

aboard_epsilon
09-05-2011, 02:49 PM
Maybe a valve in the ABS block isn't seating ..the seats of the valves can get corrosion on them.

They reckon to keep ABS good ..you should make it activate every few months ..
go to a wet empty car park ..accelerate and brake a few times .

This will remove any corrosion and seat the valves .

all the best.markj

Scottike
09-05-2011, 02:54 PM
Sigh........

Used to be, the shop would get a rebuild kit.

Now they replace the unit.

Dat bettah?

Sorry, I wasn't trying to nitpick, I just read it the wrong way.
your right - rebuild kits are becoming hard to find.

Willy
09-05-2011, 04:33 PM
JT, I think what you have run into is all too common in todays automotive repair field.
General repair shops are forced to take on work, (in order to stay solvent), which they are clearly not equipped to handle, either due to lack of knowledge and or the lack of specialized equipment required for certain procedures.

In todays increasingly complex automotive repair industry, automotive systems management is fast turning into an industry that has to specialize in order to effectively keep it's clientèle well serviced.
HVAC, transmission, OBD II, ABS, etc. are just the tip of the iceberg requiring someone trained and experienced in the nuances of diagnosis and repair of these systems.

Expecting a shop not properly trained and equipped to handle the diverse nature inherent in todays automotive systems is like expecting your family doctor to be an expert in neurological disorders or brain surgery.
True, he'll know enough about these matters to give you some advice, but he will, or should be the first to refer you to a qualified specialist.

Unfortunately the automotive repair industry is rampant with the "we can do it all" attitude due to not wanting to turn away business.
They still serve a valuable service, but like the old saying of...caveat emptor...it should probably be up to the person buying these services to seek out a qualified specialist.

It is regrettable that this is how things have gone in the industry but I'm seeing more of this as the technology in modern autos intensifies.

You may have to do a little leg work in seeking out those proficient enough, but if you ask around, and get the same recommendations from various sources, I'm confident you will find a reliable shop to do your work...just don't expect one shop to be experts in everything from electrical systems to to the new 9 speed trans-axles.
There are some very talented people out there though so don't get discouraged.

darryl
09-05-2011, 05:30 PM
I took my LandCruiser to a shop for a brake job. He called me later to say it was ready, and as I was paying he mentioned that he couldn't get the right front drum off, so he couldn't do that wheel. What? He was going to send me off with three wheels done and one untouched. I ended up paying him a reduced rate and did the last one myself. Yes, it was tough to get that drum off, but I managed. I don't have the equipment to turn the drum, but it wasn't that bad.

I got a little curious and checked the brake fluid. It was brown. It was not like that before- I know because I had checked it when I was determining if I wanted to do the job myself, or take it to a 'pro'. I ended up buying a new container of brake fluid and flushing the whole system.

Years later I went to another brake shop, with a different vehicle. They wanted to replace the discs, saying that there wasn't enough meat on them to machine. They had never been turned before. They tried to persuade me to go that route, but I insisted on keeping the original discs and having them turned. They reluctantly agreed, but suggested I'd be lucky to get 6 months out of them. They did a good job, no problem with that. Brakes have been fine for the last five or six years- no pulsing, no squealing, no soft or low pedal, no pulling to one side or the other. Chances are if I'd opted for the chinese replacement rotors I'd have been into another brake job by now.

The LandCruiser needs a master cylinder now- last time I drove it I nearly smoked a cop car. I was lucky enough that when the brakes failed I had some room to swerve into a boulevard and avoid an accident. The cop was very nice- she made sure I had the emergency brake working (that's how I did stop) and she followed me home so I could park it. I'm kind of wondering if I should get it fixed up so I can use it this winter- but it eats so much gas :(

J Tiers
09-05-2011, 09:12 PM
Maybe a valve in the ABS block isn't seating ..the seats of the valves can get corrosion on them.

They reckon to keep ABS good ..you should make it activate every few months ..
go to a wet empty car park ..accelerate and brake a few times .

This will remove any corrosion and seat the valves .

all the best.markj


Oh, that's no issue.... don't need any wet parking lot, just a tiny bump in the road....hit the brakes as you go over the microscopic bump, and the ABS will happily shut off the brakes for a second or so.

I don't know why it works on ice etc, and "falses" / fails so dramatically on dry pavement.

Drove the vehicle today......

3 startups..... 2 of three startups had no issues at all (clutch is back to working right again) one had brake failure and ABS lights.

Go figure.

Going out later, we'll see how #4 and #5 are.

M_C
09-07-2011, 03:18 AM
If they changed the Master Cylinder, it could be something simple like the Brake pedal switch needing adjusted or reset.

I'm not sure about your side of the pond, but certainly on this side, most brake pedal switches on more modern vehicles have two sets of contacts, so the various controllers that need a brake pressed signal have some way of performing a switch plausibility test.
If there's no obvious threaded adjustment, press the pedal, then pull the switch button until you feel it ratchet out, then let the pedal up so it adjusts to where it needs to be.


As for the clutch, if there's no external leak, then chances are the master cylinder is the problem. Master cylinders can randomly stop working after maintenance, due to them being moved/loaded/pressurised slightly differently during bleeding/flushing, causing the seals to fail.
Either that, or there could be a slight leak somewhere allowing air to enter, but given it seems to fix itself, then I'd expect a damp patch somewhere.
When the pedal is good, what happens if you keep it pressed for a couple of minutes then try and select gear?

terry_g
09-07-2011, 08:44 AM
I worked on a dodge truck about the same vintage. In order to get the brake and ABS lights to go out after the repair the battery had yo be disconnected for a few seconds.

Terry

J Tiers
09-07-2011, 09:13 AM
When the pedal is good, what happens if you keep it pressed for a couple of minutes then try and select gear?

it's perfect, no apparent change. I can hold the clutch for a long traffic light and it is fine.

That is even true when the clutch is down at the floor, but hasn't quite interfered with shifting yet.
.
.

As for the battery, it has been disconnected, I know that due to resetting the radio.

And it is not a problem of the lights ALWAYS being on, anyway.

It is that they come on seemingly randomly. I drove 10 miles, no warning lights. After an hour or 1.5 hours, drove a shorter distance. brake and ABS lights both on. 40 minutes later than that, drove BACK, no warning lights.

vpt
09-07-2011, 09:20 AM
Bad or loose wheel bearings can throw ABS codes and make the brake peddle funny. If the wheel bearing is loose or bad it can knock the pads back in the caliper and when you put the brakes on the peddle will travel more then usual.

It is a problem you have to put up with racing and big sticky tires. Thats why after a certain level of race car they switch to floating discs.

saltmine
09-07-2011, 12:15 PM
After reading all of the postings, I'm truly amazed that something so basic and simple has become such a problem to the technicians presently working in the automotive industry. Before retiring, I routinely diagnosed and repaired hundreds of these vehicles, successfully. We knew the systems and were properly trained to do the job. But also, we had the correct & proper tools to do the job. I'm one of the guys you seldom hear about. The guy who gets up and goes to work every day, does his job right, and doesn't have problems with it. The only mechanics that you hear about are the ones that mis-diagnose a problem, costing the customer a lot of lost time & money. Or the guy who doesn't do the job correctly and has to do it over again....sometimes repeatedly.

I have never had a problem diagnosing or repairing a clutch with a concentric release bearing. (Which, by the way, are designed to remove all of the "monkey-motion" levers and push-rods commonly used in older, less reliable systems). They do require proper training, and specialized tools to perform the repair correctly. If the "tech" don't have the training or the special tools....well, read the posts. This job should have been done right, one time, period. Same goes for the brakes. I'm sitting here, hundreds of miles away, never saw the truck, but I know the brake problem was a faulty master cylinder. How these shops get away with their incompetence is beyond me. In the day, they wouldn't have lasted two weeks putting out work like that. And then there's the experience Darryl describes....A brake job on a LandCruiser.....and the guy says they didn't do one wheel (??) because they couldn't get the brake drum off(??)...And then charged him full bore for doing three wheels and letting it out the door(??) in that condition(??). I don't know where you guys have your cars fixed, but in my neighborhood, the tech & the owner of the shop would be facing jail time for pulling a stunt like that. That's dangerous, man!

I guess I'll have to agree with Willy on this one. The auto repair business has really gone to the dogs, lately. I hope & pray I never need to have repairs I'm unable to do, myself.....

aboard_epsilon
09-07-2011, 12:26 PM
I guess I'll have to agree with Willy on this one. The auto repair business has really gone to the dogs, lately. I hope & pray I never need to have repairs I'm unable to do, myself..... __________________

You will ..when you get older ..and it will be worse then ..everything will be electronic ..diagnostics will be done by swapping and changing parts at your expense until by shear luck they find the problem.

or vehicles will be so difficult to fix that you will be buying a new one ,everytime it packs up .

all the best.markj

portlandRon
09-07-2011, 12:55 PM
If it was just the clutch I would say give the shop another chance. That system is not easy to bleed and made need to be a couple of times. However with the brake problem also I would look for another shop.

dave5605
09-07-2011, 02:38 PM
TAKE IT TO A COMPETENT MECHANIC AND QUIT SCREWING WITH IT. Yes I'm yelling.

You are going to keep messing around with it hoping its going to go away or magically gets fixed. Well its isn't going to go away and one of these times it might just fail and you are going to have an accident. What's that going to cost you?

A couple of things that haven't been mentioned are the vehicle may have a proportioning valve for the back axle that has a separate bleeder and if not bled first will cause brake failure like you are experiencing. I have also seen brake systems where after 15 minutes of pressure bleeding you are still getting air bubbles coming out of the various bleeder ports.

As for the clutch, some clutch packages can be mal adjusted and cause the clutch arms or diaphram to go over center and cause all kinds of weird symptoms.

At this point I'd probably take it to a GM dealer and let them screw with it. They have access to all kinds of internal literature, historical data bases and troubleshooting techniques that your average brake place has never seen.

saltmine
09-07-2011, 02:59 PM
I think you're missing the point or don't have any experience with this type of clutch, Dave.

A diaphram clutch has NO internal adjustments or settings. It's manufactured to very close tolerances and is either right or horribly wrong. Factory testing keeps the bad ones out of the box. Hydraulic clutches also have no adjustments, to speak of. Once installed, they are self-adjusting.

The big secret to the hydraulic clutch is correct bleeding equipment. Most garages and even some dealers don't have access to a reverse bleed unit like the "Phoenix Bleeder". Using this type of bleeder is essential to get all of the air out of hydraulic clutches and ABS brake systems. Of course, the guy using it has to know how to use it.

I've seen techs virtually bleed a system all day long and get nowhere with it, using conventional means of bleeding.

I've also seen techs want to tear all of their hair out while trying to bleed a concentric clutch on an S-10 or a Ranger, then, step in, with a reverse type bleeder and complete the task in a matter of minutes, with a minimal loss of fluid.

By the way, loose wheel bearings can cause a somewhat low pedal. But on most of today's split dual master cylinder systems, the brake pedal height is set by the rear brakes, not the front. Having loose wheel bearings on a vehicle is evidence of poor maintenance. And letting a vehicle go out the door with loose bearings, especially after a brake job, borders on a criminal act.

vpt
09-07-2011, 06:36 PM
I'm sitting here, hundreds of miles away, never saw the truck, but I know the brake problem was a faulty master cylinder.


Thats what I thought too but the master was mentioned in the OP and was a little unclear if it was replaced or not.

With the fluids being flushed and everything else in good working order the only other culprit to changing brake peddle travel is normally one or more bad wheel bearings. Bad wheel bearings ALSO throw ABS fault codes which the OP also mentioned having.

vpt
09-07-2011, 06:39 PM
Hydraulic clutches also have no adjustments

Actually most do have adjustment but it is done with the clutch rod on the clutch peddle arm.

J Tiers
09-07-2011, 09:39 PM
1) There is NO adjustment on the clutch system.....

the system was not bled right to begin with, so it had release point on the floor soon after the repair.

it was bled BY ANOTHER SHOP, in another state, that I KNOW does S10 business, two were in there when mine was. it worked perfectly for 30 days.

Now the clutch release point has been up and down from floor to normal at least 10 times, with NO action other than driving it to explain that.

2) There has been NO EVIDENCE of actual brake "failure" since the last repair.

I TOLD them the master cyl was bad, since the pedal was going to floor (slowly, it still stopped the truck). They could not reproduce the problem, which I told them was intermittent.

I TOLD THEM to replace the ^%$# thing and get it over with, that I wasn't trying to save a buck by waiting until it crapped 100%.* They did, but complained that they didn't KNOW for sure it was bad, by personal experience. But they agreed that what I described was a bad M/C.

Since then, there has been no "failure"....... There HAVE been "warning lights", the cause of which is unknown, but presumably has to do with the brake repair.

Lights are brake and ABS "failure" lights..... But both the brakes AND the ABS are known to work, since it stops normally, with normal pedal pressure.

The ABS has been happily "falsing" on bumps and also just as the truck comes to a stop**, same as it always does, and has done for 11 years.

* I believe in "airline" maintenance..... some stuff gets replaced even though it has not failed yet.... just because it's due, and I hate getting towed. That's what is so irritating.... do the right thing, and get nailed for it.

** The ABS comes on for a second right after the truck stops, (always has), makes a "clunk/buzz" right after coming to a stop. It still does that.

M_C
09-08-2011, 02:50 PM
A diaphram clutch has NO internal adjustments or settings. It's manufactured to very close tolerances and is either right or horribly wrong. Factory testing keeps the bad ones out of the box. Hydraulic clutches also have no adjustments, to speak of. Once installed, they are self-adjusting.

Self Adjusting Clutches clutches are pretty common place in europe now - http://www.luk.de/content.luk.de/en/products/clutch_systems_new/clutch_pressure_plates_new/sac1_new/SAC1_new.jsp

But I agree with your comments about the standard of work.
I spend a large part of my week sorting other guys f**k ups.

M_C
09-08-2011, 02:54 PM
2) There has been NO EVIDENCE of actual brake "failure" since the last repair.
<trimmed>

Sounds like too big an air gap on some of the ABS sensors, which can be caused by the sensor being disturbed/knocked during other work, or something mechanical like a wheel bearing with too much play.

With suitable diagnostic kit, it should be a five minute job to see where the problem is (on a datalog screen, you can see at what speed each sensor stops recording, and the one(s) that vary from the rest is where you start looking for the problem)

aboard_epsilon
09-08-2011, 03:02 PM
A bit of a problem over here with abs is the reluctor rings cracking ..usually salt gets behind them causes rust and they crack across the teeth....if you not a machinist it means a new drive shaft sometimes.

http://www.evilution.co.uk/smartchassis/reluctor/reluctor3.jpg

all the best.markj

saltmine
09-08-2011, 04:50 PM
I used to supervise five techs, and perform all of the diagnostic and heavier repair work in our County fleet shop. Sometimes it meant driving several hundred miles to perform a diagnosis or repair at one of our "satellite" shops, stay the night, and drive back to the main shop the next day.
Even the best people I had in the shop were poorly equipped to diagnose or repair most problems we encountered....Saying that, if you guessed I was busy, you'd be right. When I retired, the department supervisors went bat**** crazy (I'm pretty sure they slept upside down) trying to find somebody to replace me. From what I hear from the Deputies and County Employees, they still haven't found a suitable replacement (I retired in 2005). One friend claims they have an extra four zombies stumbling around in the shop, and practically everything I used to handle in the shop gets "farmed out" to retail shops and dealers. Too bad, the department head wanted me gone, and once told me he could replace me with two guys off the street for half of what they paid me....I guess it never happened...Their maintenance budget had to be increased by 40% to keep the county vehicles running.....after I left.

J Tiers
09-08-2011, 08:34 PM
A bit of a problem over here with abs is the reluctor rings cracking ..usually salt gets behind them causes rust and they crack across the teeth....if you not a machinist it means a new drive shaft sometimes.


all the best.markj


The ABS has been AFU on dry pavement since the truck was NEW......

Gravy
09-08-2011, 08:50 PM
I used to supervise five techs, and perform all of the diagnostic and heavier repair work in our County fleet shop. Sometimes it meant driving several hundred miles to perform a diagnosis or repair at one of our "satellite" shops, stay the night, and drive back to the main shop the next day.
Even the best people I had in the shop were poorly equipped to diagnose or repair most problems we encountered....Saying that, if you guessed I was busy, you'd be right. When I retired, the department supervisors went bat**** crazy (I'm pretty sure they slept upside down) trying to find somebody to replace me. From what I hear from the Deputies and County Employees, they still haven't found a suitable replacement (I retired in 2005). One friend claims they have an extra four zombies stumbling around in the shop, and practically everything I used to handle in the shop gets "farmed out" to retail shops and dealers. Too bad, the department head wanted me gone, and once told me he could replace me with two guys off the street for half of what they paid me....I guess it never happened...Their maintenance budget had to be increased by 40% to keep the county vehicles running.....after I left.

It's a sad commentary on the state of the world...but I believe you. There are a handful of other members here who get it, too.

Reminds me of a long and boring story:

I've heard the "I can replace you in a minute" speech from some service manager/salesjerk several times. Most of them were blowing smoke pro-forma as a management technique, but one of them really thought it worked. He loved bait and switch with both the employees and customers. (Insert slimeball story here).

I found a better job and gave my two weeks' notice.

He called me in for an "Exit interview" and tried to convince me to stay. He pasted an earnest, wide-eyed look on his face and pretended that he had always respected my abilities and efforts. He asked what they could do to keep me on.

I enjoyed the look on his face when I explained exactly *why* I wouldn't stay. "You are a phony and a liar and nobody believes you except the owner" (or words to that effect).

Mr. Slick's jaw literally dropped. He turned pale, and then red. He stammered out a few words "thanking me for my honesty" and left in a hurry.

In retrospect, that may not have been the wisest thing I ever did. It worked out because I had a solid job waiting, but I don't think I'd do it again:eek: (I'd probably say something diplomatic about expanding my horizons.)

Sound familiar?

Gravy
09-08-2011, 09:40 PM
The ABS has been AFU on dry pavement since the truck was NEW......

Yours was wrong from the factory. Bad ABS is worse than useless, but good ABS is priceless. I think it depends on whether the critical decisions were made by engineers or accountants.

For a while, GM let accountants make too many engineering decisions.

J Tiers
09-08-2011, 10:45 PM
Drove home from work.... stopped and turned off twice, no warning lights.

Drove out later, (after shop was closed) two big old "you gonna die" lights...... stopped at destination.....

Drove out from there 40 min later..... no lights.

Stopped 10 or 15 min at store on way home.....

Driving out from there... two big ol' lights......

For sure, no lights when the shop is open.

Do they set codes? If so, they won't call me a liar. I've been trying to get near the shop with lights on.... so I can stop in and holler for the boss..... and he will see them.

I don't think anything is really "wrong" with it, but something is convincing the system that there is.


Yours was wrong from the factory. Bad ABS is worse than useless, but good ABS is priceless. I think it depends on whether the critical decisions were made by engineers or accountants.



it works fine on ice.... Does everything it should then.

But it falses like crazy on dry pavement with bumps when stopping. Rolls me out in intersections sometimes. Always has.

Dealer comment was basically "it's not throwing codes, we aren't allowed to do anything to it."

I'd disconnect it except for the way that would make everything my fault in any accident. No matter if the other person was 100% at fault..... disconnected ABS would throw it all on me.

lakeside53
09-08-2011, 11:13 PM
I have 20 year old abs on my truck. Perfect... 13 year old on my Subaru - perfect... dry, ice wet - no matter.

Get it fixed.. surely someone knows how to in your area. Or... if it's such a lemon, take it to a scrap yard - $500.... and buy something that works.

Iraiam
09-08-2011, 11:15 PM
The soft pedal sounds like the check valve in the master cylinder, often caused by the Brake fluid getting old and collecting sludge in the reservoir. Then when a brake job is done on it and the reservoir is topped off it disturbs the sludge and it gets in the check valve. The sludge is rust, brake fluid is notorious for pulling in moisture.

Get yourself the one man brake bleeder kit from Harbor Freight, it is handy as all get out. A bottle for the master cylinder reservoir and a venturi vacuum generator for the bleeder vacuum.

start at the wheel farthest from the master cylinder and pull fluid through the system until it comes out clean, do this on all four wheels. I have saved many master cylinders by just getting good clean fluid in the system.

It's definitely worth a try on your hydraulic clutch system also.

good luck

J Tiers
09-08-2011, 11:27 PM
Get it fixed.. surely someone knows how to in your area. Or... if it's such a lemon, take it to a scrap yard - $500.... and buy something that works.

NOT.... bad idea, no cornflakes for lakeside.

The ABS sucks on dry pavement... The truck is fine otherwise..... until the wheels fall off it ain't goin to NO scrapyard whatever....

Just for the record......

The original question here was "is this such an odd problem that it is legit for it to be an issue to fix, OR is it just that the shop is clueless?"

it ain't about the truck it's about the shop.....

Now, I could take it to the dealer.... I usually do, but I can walk back from the shop, and they were highly recommended by several folks. The dealer is a hassle to get to. And they are no prize.....

And, these guys need to make good.... if I have to go to the dealer, I'll lose the money spent with the shop, and may have to pay for the whole job over again, PLUS new parts. I would be ready to strangle someone with their own chitlins at that point..... after slitting them from their guggle to their zatch. I'd not get to drive the truck then, no matter how perfectly fixed is was, jail is like that.

But if the shop fixes their (presumed) mess-up, it's on their nickel for time, it's warranteed. And I stay out of jail.

psomero
09-08-2011, 11:49 PM
Sigh........

Used to be, the shop would get a rebuild kit.

Now they replace the unit.

Dat bettah?



is the replacement unit brand new or remanufactured?

J Tiers
09-09-2011, 12:03 AM
is the replacement unit brand new or remanufactured?

methinks it is new...... based on cost...... never occurred to me it might be rebuilt by "Bubba and Moe" Inc..... :eek:

aboard_epsilon
09-09-2011, 07:27 AM
The ABS has been AFU on dry pavement since the truck was NEW......

AFU ?

Take the wheels off have a good look at the reluctor rings, they may have been loose since new ..while you're there, have a look at the detctor heads / sensors.

all the best.markj

vpt
09-09-2011, 08:48 AM
methinks it is new...... based on cost...... never occurred to me it might be rebuilt by "Bubba and Moe" Inc..... :eek:


Most "shops" get their parts from the same parts store everyone in town gets their parts from and if it can be rebuilt it is. Any time you get something replaced on any vehicle ask for the old part back. Not only so you know they actually replaced the part they said they did but also if they say they can't give it back it is because your old part is being returned to get rebuilt and sold to some other guy.

Joe Rogers
09-09-2011, 11:27 AM
Most "shops" get their parts from the same parts store everyone in town gets their parts from and if it can be rebuilt it is. Any time you get something replaced on any vehicle ask for the old part back. Not only so you know they actually replaced the part they said they did but also if they say they can't give it back it is because your old part is being returned to get rebuilt and sold to some other guy.

Not sure that is a great idea. The parts manufacturers are influenced by the competition in the market. If the rebuilders capture a portion of the market the manufacturers compete on price to hold market share. This drives the price down and the consumers benefit. At least that is the way I see it.
If a rebuilt part is defective or fails in use during the warranty period then seek remedy on that part. Keep everyone in the industry honest and competitive.
Joe

saltmine
09-09-2011, 11:29 AM
That's one mistake many shops make when they attempt to bleed ABS brakes. They either try to do the bleeding with two guys (traditionally) with one opening the bleed screws, one by one, and the other pumping the brake pedal....Or they hook up a conventional pressure bleeder and spend hours watching fluid dribble out the bleed screws.
By it's design and very nature an ABS brake unit is almost impossible to force fluid through....from the master cylinder. Due to the various accumulators and check/balance valves inside the ABS, very little, if any, fluid will make it's way through the unit and out to the bleed screws at the wheels. If you consult the GM Factory Unit Repair Shop Manual (brake section) it's quite plainly written out that a reverse or "specialty" type brake bleeder should be used to remove the air from ANY ABS brake system.
Why reverse? Because fluid flowing from the wheel cylinders back to the master cylinder, through the ABS unit, HAS to be unrestricted in order to release the brakes properly. The point is: we're not working on a 1956 Ford sedan here....it's a modern, state-of-the-art, truck with anti-lock brakes.
And what worked on your Dad's Hudson doesn't play well here.

Iraiam
09-09-2011, 08:26 PM
That's one mistake many shops make when they attempt to bleed ABS brakes. They either try to do the bleeding with two guys (traditionally) with one opening the bleed screws, one by one, and the other pumping the brake pedal....Or they hook up a conventional pressure bleeder and spend hours watching fluid dribble out the bleed screws.
By it's design and very nature an ABS brake unit is almost impossible to force fluid through....from the master cylinder. Due to the various accumulators and check/balance valves inside the ABS, very little, if any, fluid will make it's way through the unit and out to the bleed screws at the wheels. If you consult the GM Factory Unit Repair Shop Manual (brake section) it's quite plainly written out that a reverse or "specialty" type brake bleeder should be used to remove the air from ANY ABS brake system.
Why reverse? Because fluid flowing from the wheel cylinders back to the master cylinder, through the ABS unit, HAS to be unrestricted in order to release the brakes properly. The point is: we're not working on a 1956 Ford sedan here....it's a modern, state-of-the-art, truck with anti-lock brakes.
And what worked on your Dad's Hudson doesn't play well here.




You are correct, if you try and push the fluid from the master cylinder to an open bleeder at the wheel it won't work right with ABS.

If you pull a vacuum on the the open bleeder valve, you can pull as much fluid as you want easily from the master cylinder all the way through and out of the open bleeder valve.

That's why I recommended the Harbor freight, brake fluid bleeder setup, works perfectly every time, even with ABS.

saltmine
09-09-2011, 10:16 PM
Uh, that's not the way it works.

The bleeder I have has a reservoir filled with brake fluid and a hand pump.
The pump is connected with an open bleeder valve and fluid is forced back through the system, into the master cylinder. The big thing you have to watch is fluid overflowing out of the master cylinder.....That's why it's called a reverse bleeder.

Pulling a vacuum on a bleeder valve doesn't do any better than pressurizing the reservoir of the master cylinder.

Iraiam
09-09-2011, 10:34 PM
Uh, that's not the way it works.

The bleeder I have has a reservoir filled with brake fluid and a hand pump.
The pump is connected with an open bleeder valve and fluid is forced back through the system, into the master cylinder. The big thing you have to watch is fluid overflowing out of the master cylinder.....That's why it's called a reverse bleeder.

Pulling a vacuum on a bleeder valve doesn't do any better than pressurizing the reservoir of the master cylinder.


Then it must be my formerly unknown super powers, My bleeder is a vacuum system, it functions as I described ant it has worked on every ABS vehicle I have used it on.

The latest was a 2007 Explorer Sport Track XLT. After the brakes were done I replaced the brake fluid by pulling all the fluid out via the bleeders, a bottle goes on the reservoir to gravity feed new fluid in as it gets drawn out, and a vacuum generator gets hooked to the open bleeder valves and pulls all the fluid out. Although on a system with a separate ABS reservoir, I'd have to do it twice to get clean fluid in there also.

I replaced every drop, had full pedal and all ABS functions are ok, easy peasy.

aboard_epsilon
09-10-2011, 06:57 AM
Years ago there used to be designs of bleeders in all the diy car fix mags tips sections, that used the vacuum from the engine to pull the fluid out of the bleeds into a jam jar of sorts .

cant find a picture of it ..

but here's the same idea with a vacuum cleaner ..

http://i179.photobucket.com/albums/w293/moggie99/website/mk1%20820/39.jpg

http://t1.gstatic.com/images?q=tbn:ANd9GcQh7yWcI_6QW5yHkqQGTQk2hdC8mzMQo Xl0gnH352F_GxsxJN-rWZOw2rWcNw

so instead you put a tube to the inlet manifold ..should be a spare take off there or two.

---------------------------------------------------------------------------------------------------------------------

this is what i use ..air over hydraulic ..i have abs

and it works well..it uses the spare wheel as the air source.

http://www.benzworld.org/forums/attachments/r129-sl-class/363251d1300274176-soft-brakes-eezibleed-2.jpg



all the best.markj

vpt
09-10-2011, 10:22 AM
I don't like vacuum bleeders. There is nothing like 2400PSI pushing bubbles out of the system. 20 inches of mercury vacuum just doesn't get them all out all the time.

For the chevys ABS systems, lol, I normally put the truck up on the lift and run it in gear while pumping the brakes. It cycles the abs unit and after done enough gets the air out. The right way is with a computer that cycles the unit automatically but I can find lots of other tools to spend the $1000 on.

Back feeding the fluid threw the bleeder does not work! Air always rises to the top (common sense) and if you look the soft brake lines connect to the calipers in the middle of the piston reservoir. The air in the piston cavity will not travel down and into the line then threw the ABS and up to the master. PLUS you are absolutely not supposed to push the dirty brake fluid in the caliper back threw the entire system, that is how you ruin components with contamination like the ABS unit, prop valves, and masters.

Fresh fluid in the top - old fluid out the bottom - pressure creates flow which pushes bubbles - cycle the abs unit and finish up.

aboard_epsilon
09-10-2011, 10:53 AM
I don't understand ..just had a look at eBay ..they have some very expensive brake bleeders on there some costing £775 ..that basically do the same thing, work the same way, as my Gunsons EaZy-Bleed that cost me £10...shown in the last picture of my last post above ..

I cant find any bleeder that pumps it in reverse ..for a start you'd never seal the line completely at the bleeding nipple....there would be a whole load of mess when the master cylinder overflows..you'd have to empty the master cylinder to start the job ..think saltmines post about such a system was an April fools joke. :D

all the best.markj

saltmine
09-10-2011, 12:06 PM
The "Phoenix Bleeder" is probably the only one on the market that uses a hand pump to reverse bleed systems. One of the biggest problems with the vacuum bleed system is sealing the bleeder screw while it's open. Outside (atmospheric air) can make it's way past the threads of the bleeder. This doesn't happen with a reverse bleeder because you have pressure on the bleed screw and may encounter a slight leak of brake fluid around the threads. The other advantage of a reverse bleeder is hydraulic clutches. Bleeding by hand or with a common pressure bleeder is nearly impossible to get the air out of some clutch cylinders, unless you have a way to turn the cylinder up & down, every direction. A reverse bleeder will clear all of the air bubbles in a matter of seconds.

BTW, VPT. If reverse bleeding doesn't work, HOW IN THE HELL DO YOU RELEASE YOUR BRAKES WHEN YOU TAKE YOUR FOOT OFF THE PEDAL?? (most ABS systems can be placed in the "bleed" mode with a scan tool, also)

No, it wasn't an April Fool's joke, Epsilon....Google "Phoenix Brake Bleeder"

But what do I know, I've only been doing this for 45 years, and have been retired longer than some guys have ever been working on cars.

vpt
09-10-2011, 12:40 PM
Nothing like pushing that dirt up into the fine hydraulics. Is that how you got repeat customers? Replace brake pads, push dirt into abs unit and master, customer comes back for master and abs work later on. Win win, job security, and whatnot.

Max_Power
09-10-2011, 12:50 PM
I'm kinda a lurker here, And I won't claim I've never had a car "eat my lunch"...Any good mechanic who is honest will admit that. Thats how we learn!. I think finding another independent shop to take a look at it would be a good idea, preferably one where the owner of the shop turns wrenches and has his name on the sign. I have had this same issue on GM pickups a few times in my 25 years as a transmission technician. These slave cylinders can be VERY frustrating to get bled.

1. If you have to do it again, I highly suggest replacing the clutch master cylinder at the same time as the slave. and vice versa. Seems the other one will always fail soon after one is replaced, And some new units are pre-filled with a brake fluid soluble "gel" that displaces air and makes bleeding easier.

2. Make sure you don't cycle either unit dry, as it can damage a new unit instantly.

3. "bench bleed" any master or slave cylinders before installation when you can rotate them at funny angles and let bubbles escape, a fingertip over the port as a "checkvalve" only letting fluid out works well.

4. Usually these clutch slave cylinders come with the plastic pressure line installed. Rough handling can crack this line so check it.

5. Many times when these systems would not bleed, I have used the following technique: disconnect pressure line from the clutch master cylinder, have a syringe to fill the top of the line directly or use a tiny funnel that will fit in the line, etc. Then have a helper go down with a small prybar or big screwdriver and stick it through the hole where the lines enter the bellhousing, and slowly pump THE SLAVE CYLINDER by pushing on the throwout bearing . push it all the way back and then while making sure the line up top is always full of fluid let it slowly spring return it to its resting position against the pressure plate. Its much easier to get bubbles to float up than to try to push them down to the bleeder on the slave. When you get no more bubbles from pumping the slave, fill the line to the top with the syringe, the using the "fingertip check valve" method and a helper at the pedal, bleed the master cylinder till no air purges, them remove your finger quickly and reconnect the line(usually a roll pin retains it in the master, which is why these things are so hard to bleed..no real purgeable fitting at the master) The bubble that got into the top of the line when reconnecting will usually float through the master and get purged into the reservoir by itself after a few pumps.

6. I cant promise it does on this year model, But many of these systems do have a adjustment where the clutch master connects to the pedal. A incorrect adjustment here can not allow the piston is the master to retract enough to uncover the port where fluid is recieved from the reservoir and not allow fluid to replace the air that you are letting out.

7. As far as the brakes, first step is to get a trouble code when the light comes on. A lot of these vehicles will "forget the code" when turned off, So next time it comes on take it to someone who can pull the code but don't turn off the ignition, just kill it with the clutch and leave the key on until the code can be retrieved. Most of these trucks are rear abs only and use the VSS "speedometer signal" from the transmission to calculate rear wheel speed, and cant differentiate between the left or right wheel. The later ones are true four wheel, But I'm thinking your model is possibly RABS. either way, the code will tell you which direction to head.

I'll check my reference materials to make sure im associating the right ABS system to year model in my head, But I'm pretty sure my clutch bleeding technique will work, as I've spent a whole day many times before trying to bleed one and this technique finally saved me. Good luck with it! Todd

aboard_epsilon
09-10-2011, 02:16 PM
"Phoenix Brake Bleeder"

You know .

Some people have an unlucky number

believe it or ..it's true this is. I have an unlucky word .
and that word is phoenix ...i think its a bad word ..and drags around with it bad luck.

Lots of company's that go bust ..will rise again with the new name phoenix..then a couple years later will fall again .

Rover the car maker was sold to the phoenix
Consortium...lasted about 4 years ..then died.

my mortgage endowment plan was taken over by phoenix ..made bugger all after that.

other investments ..of mine were also taken over by another phoenix ..this blinking name is following me around.

one once prestigious factory in prestatyn ..was re-named the phoenix works..and operated by phoenix developments ..and didnt last long after that.

All the best.markj

justanengineer
09-10-2011, 04:21 PM
From the sounds of it, you went to a rather clueless shop. As some mentioned previously it sounds like you have issues within the ABS system, which shouldnt prove difficult or be an issue for a decent shop to sort out - it really isnt that complicated of a system.

Regarding the clutch, you should be looking into pushing your boot up the PO of the truck's backside. IMHO clutches are something that shouldnt go bad within the normal life of the truck unless youre doing a lot of towing/heavy hauling or are an abusive driver. Being an S10, it shouldnt be much of the previous, so I would seriously suspect the later. My immediate family owns three S10s from 97-02, two of which are over 200k, and none have needed clutches despite rather rough use on the farm at times and city commuting duties.

J Tiers
09-10-2011, 10:39 PM
AFAIK the vehicle is 4 wheel ABS.....

OTHERWISE why does it instantly and heavily veer to the side if ABS is falsely triggered on a bump that the front wheels hit?

THIS ABS WORKS GREAT...... ON SLIPPERY SURFACES.

I am not buying into an ABS problem that is not a design issue.

besides that, there are TWO warning lights.... NOT JUST ABS. There is a brake failure light also. I get either BOTH OR NONE.

WEll, today I got the pleasure of driving back 25 miles in second gear, which was the only one that I could force the tranny into and that I could start from stop in (I have a granny gear rear ratio). Clutch pedal did its ""I won't release until I am on the floor" deal and didn't improve.

First time this happened, I had another shop (600 miles from the first one) bleed the system, and that got it back to perfect again. Lasted 30 days with NO problems, and no change in operation before it got intermittent.

In order to reduce the chances of being jailed for slitting people from guggle to zatch, and because they are convenient, open, and owe me the work to fix it right, I took it back to the original folks, and told them my issues in detail, using firm, polite "no I am not happy and I am cold and dangerous and you better do it right" tones of voice, along with appropriate "I am not threatening anyone.....yet" body language.

The shop foreman said all the right stuff, so he KNOWS what to do..... all that needs to happen seems to be for the mechanic to DO that.

We will see.

If no results from this visit, and for some reason no guggle slitting has been done, it is going to the dealer, who will no doubt want to replace all the same stuff again :mad:

As for abusive P.O. burning the clutch............. that would have to be me...... I bought it new. But since I have been known to drive a bad clutch another 50k miles, I don't think I burnt it.

However, it has been getting "odd", and has had issues of squeaking loudly when starting up hills or under heavy load, etc, etc. Just didn't feel right as it engaged (nothing to do with the pedal).

All of that stopped with the new clutch.

Remember it's a 2000, so newer than the '92, with more cost cutting and material thinning and lightening...... It might well wear out faster than a '92.

Joe Rogers
09-10-2011, 11:11 PM
"besides that, there are TWO warning lights.... NOT JUST ABS. There is a brake failure light also. I get either BOTH OR NONE."

This is the way it is designed to work. The logic is the ABS will shut off if the basic brake system has a safety fault. Indicated by THE RED LIGHT. If it is lit the ABS lamp will come on BY DESIGN. Chances are there is no ABS fault other than a default shut down due to the basic brake fault. If the ABS system had a fault it could light the ABS indicator and the red brake warning lamp would not light.
Joe

J Tiers
09-10-2011, 11:16 PM
"besides that, there are TWO warning lights.... NOT JUST ABS. There is a brake failure light also. I get either BOTH OR NONE."

This is the way it is designed to work. The logic is the ABS will shut off if the basic brake system has a safety fault. Indicated by THE RED LIGHT. If it is lit the ABS lamp will come on BY DESIGN. Chances are there is no ABS fault other than a default shut down due to the basic brake fault. If the ABS system had a fault it could light the ABS indicator and the red brake warning lamp would not light.
Joe

Perzactly...... There is likely no ABS issue, and the issue is something in the regular brakes, which the shop worked on.

The lights come on at the beginning of the trip, usually they are seen before the vehicle even starts moving. Sometimes after, but ALWAYS within 30 sec of releasing the parking brake. if they do not by then, they are not going to.

BTW, repeating myself, the ABS is known to work perfectly, it rained (finally), and the ABS went off as it should on a front wheel skid downhill on sharp curve. Naturally the lights were not on for that trip.

Also BTW..... the brakes always work normally with NO indication of a failure, regardless of whether the lights are on or not.

v860rich
09-10-2011, 11:49 PM
The lights come on at the beginning of the trip, usually they are seen before the vehicle even starts moving. Sometimes after, but ALWAYS within 30 sec of releasing the parking brake. if they do not by then, they are not going to.

This sentence just jogged my memory, I had a pre ABS S/10 with a weak return spring on the emer. brake pedal. You would be driving along and the pedal would move towards the applied position causing the Brake warning light to come on, figured it out pretty quick that if I pulled it back up with my toe the light went back off.

I think I shortened the return spring for the fix.

THANX RICH

People say I'm getting crankier as I get older. That's not it. I just find I enjoy annoying people a lot more now. Especially younger people!!!

Max_Power
09-11-2011, 01:03 AM
You're right, My bad...looks like the RABS as standard option ended in 1996, So yours is 4 wheel.

Even if there is no ABS problem, knowing the trouble code will let you know why the computer is interpreting there "IS" and turning on the lights. Then the parameters that set the code can be researched and more specific testing can be done. The computer turns the lights on so it "thinks" there is a problem even if it is within the standard brake switches, etc and not a failed abs component. Sometimes there will even be freeze-frame data recorded from all sensors and switches at the point the failure occurred to find intermitent problems. Makes a good "clue". Cars do funny things sometimes.... theorizing about why it can't be this or that instead of just going through the diagnostic flowchart and doing the tests can throw you off. People will go through the whole list of parts saying "I absolutely KNOW that part is good" about every single part...but obviously one of them is bad or there wouldnt be a problem? Not trying to be a smartass...just trying to help.

Question...when the clutch fails to disengage does the pedal feel change IE can you still feel it "break over" like a compound bow? Or does it just fail to disengage? Another quite common failure is the roller pilot bearing will explode and damage the transmission input shaft so that even if the bearing is replaced with the clutch job you still have a problem as the input shaft IS the inner race to the roller bearing and will quickly destroy the new bearing. This causes the trans to be coupled to the crankshaft even when the disk is released. Sounds like at least you have the foreman interested at this point. Sometimes this stuff can be just as frustrating for the technician as the vehicle owner....If youre dealing with someone with an consience anyway, Again... hope they get it solved for ya soon, sounds frustrating

bruto
09-11-2011, 01:21 AM
Side note. I have the factory service manual for the 98 S series trucks, and glanced at the brake section. It calls for either conventional (pedal pushing) bleeding or pressure bleeding. It does mention that if you suspect air in the ABS modulator you must bleed that separately. However, no call for reverse bleeding on this system.

saltmine
09-11-2011, 02:15 AM
Thanks guys. I guess I've been successfully repairing cars & trucks for the past 45-50 years, not knowing what I'm doing.

I'm so glad to have found a forum where people who have never worked on cars or trucks professionally know so much more than I do.

I tried to help. Help isn't appreciated.....unless you're being charged an outrageous sum of money...My bad, I offered my experience for free.

aboard_epsilon
09-11-2011, 08:51 AM
saltmine..JUST IGNORE ..

I.m not having a go at you, honest .

it's true about the word phoenix though ..

but, a far as brakes are concerned ..methods of bleeding etc ..i want to hear it from every angle ..

and will plonk in ..is this bad etc ..to get more responses and more discussion etc.

all the best.markj

J Tiers
09-11-2011, 09:59 AM
Question...when the clutch fails to disengage does the pedal feel change IE can you still feel it "break over" like a compound bow? Or does it just fail to disengage? Another quite common failure is the roller pilot bearing will explode and damage the transmission input shaft so that even if the bearing is replaced with the clutch job you still have a problem as the input shaft IS the inner race to the roller bearing and will quickly destroy the new bearing. This causes the trans to be coupled to the crankshaft even when the disk is released.

The clutch pedal resistance changes, and instead of a change halfway down, as the force is applied to the clutch, it is weak all the way down to near the floor.... with a slight change.

As I said originally, the clutch release point has been down to floor and up again several times.....

This time it never came back up. When this was the case before, it was bled, and that fixed it up perfectly.

But after it needs it TWICE, one has to think there is another cause.

Yes, the clutch Master Cylinder could be bad.... but it's mighty funny that it was bad less than 24 hours after I picked up the vehicle...... AND that it magically became 'good" again after being bled...

And it HAS BEEN good, I could hold pedal in for 5 min and nothing changed as far as release point, engagement point, etc.... All it really has to do is apply and hold pressure, which it seems to do.

As for fixing things... having done it for pay in my varied career, I can ASSURE YOU that THE PART THAT ABSOLUTELY CANNOT BE BAD......... THAT is the one that very often IS bad when all is said and done.

it is, however, rare for it to be bad when it can be SHOWN to work correctly..... Usually the above is true only when the "can't be bad" part is merely ASSUMED to be good. There are exceptions......

snowman
09-11-2011, 10:19 AM
Saltmine,

Just out of curiosity...and I'll openly admit I'm a driveway mechanic that does my own work just to save money....I do not do it for other people.

I've been a conventional two man bleeder for a long time. I recently switched to one man, with a hose and a reservoir at the wheel...but that's just because I hate fighting with my wife because she can't follow basic directions :-)

It's my understanding that some of the worst fluid is in the calipers, due to the higher heat and greater degradation because of that heat. When reverse bleeding, you are pushing that fluid up in to the ABS system seals as well as the master cylinder. It seems to make sense that this would be detrimental to the life of these parts.

Is it better to gravity bleed a bit out first to drain the caliper, then reverse bleed so you essentially get rid of the dirty crap before flushing...or does the dirtier fluid realistically not make much of a difference?

Also, it seems that you would still have to engage the ABS modulator with a scanner of some sort, because without opening the valve, you will stll have air trapped.

Not in any way questioning your experience, well...actually, I am questioning your experience, so that I can learn.

aboard_epsilon
09-11-2011, 10:20 AM
Some methods of bleeding can damage seals

Especially the old method of having one guy pumping the pedal and another guy opening the nipple

This can sometimes take the piston to areas were it hasn't been before ..and damage the seals on those NOW rusty areas ..

So ..you took it back and it was right after ..

These mechs have some tricks up their sleeves ..such as putting some substance or other into the brake fluid that could swell the seals ..and make it look good for a couple of hundred miles.

They know some brake fluids swell the seals etc ..

Think you've been had to be honest.

I've never trusted any of them since i had my first motorbike when i was 17 ..by 18 or so ..i trusted them that much ..that i learnt all about the ins and outs of mechanics ..and did it myself...no one else , but me, has worked on anything i have owned since then.

all the best.markj

snowman
09-11-2011, 10:35 AM
Yes, the clutch Master Cylinder could be bad.... but it's mighty funny that it was bad less than 24 hours after I picked up the vehicle...... AND that it magically became 'good" again after being bled...


First, I will restate something somone else said a long time ago....
"After replacing a clutch pressure plate, it will have a higher clamping force and need a little more pressure to open it. Higher pressure for the hydraulic system, but a marginal master cylinder will start to fail. One solution is to start pumping it, if that helps... time to replace the master cylinder."

Following a bleed, it can be hard to say...but there is the possibility that they flushed enough gunk into the master cylinder that it then sealed well enough to carry the higher pressures...but then failed after further use.

Given the cost, I would probably just replace the mc on the clutch, bleed appropriately, and know that there is nothing else that could be causing the problem other than the slave...and in that case, you can go back to the shop where you had the work done and give em hell (or at least require that they warranty out the slave)

The reality is however that you are wasting time by debating it, without looking at it yourself, or having another more qualified mechanic look at it. This is one of those answers you aren't going to find in theory, and it's not going to fix itself.

As for all of the people that think cars are hard to work on, it merely takes an understanding of the principles of engine control systems. The computer only tells you that the sensor isn't giving values it recognizes as being good, it's your job to determine if the sensor is failed (they all have values specified in the OEM repair manual) or if the sensor is good, but is reading off a fault in itself. Wrenching is no longer the job of someone who thinks electronics require a degree in wizarding from hogwarts or a machine that fills parts with blue smoke.

A.K. Boomer
09-11-2011, 10:45 AM
Years ago there used to be designs of bleeders in all the diy car fix mags tips sections, that used the vacuum from the engine to pull the fluid out of the bleeds into a jam jar of sorts .

cant find a picture of it ..

but here's the same idea with a vacuum cleaner ..

http://i179.photobucket.com/albums/w293/moggie99/website/mk1%20820/39.jpg

j


WOW - crazy set-up and one I would not recommend - for one it leaves all kinds of air pockets inside the system.

You cannot beat physically pumping the pedal and putting things through there paces to remove all bubbles - you can achieve this with a couple people with one on the pedal and one at the bleeders or if solo you can simply get a beer bottle and fill it half full of old brake fluid - then run a hose from bleeder to bottle and submerge hose, pump brakes with bleeder open several times and then close bleeder- done deal.

J Tiers
09-11-2011, 10:57 AM
Following a bleed, it can be hard to say...but there is the possibility that they flushed enough gunk into the master cylinder

The reality is however that you are wasting time by debating it,

Who's debating? I can post while teh vehicle is in a shop, I assume......

Just looking for "sanity checks" on the process. Not something I usually do, because I generally have no problems with repairs being done. I used to do it all myself, engine apart in driveway over New Years at -15C, that kind of crap. Done with it, no interest in more.

they owe me a fixed vehicle, they have it in their shop to fix now, and I WILL have a fixed vehicle, with or without the smoking livers of the guys who owe me the work.

I might remind you that the bleeding was done by a shop that was 600 miles away, KNOWN to be smart (the FIL, a diesel mechanic, uses them because he hates working on cars too) and who LOOKED FOR CRUD because I asked them to. nothing found.

Unlikely that the ONE piece of crud ended up sealing THE ONE leak in the M/C at JUST the time that the bleeding was done..... I am not a big believer in co-incidences.... obviously it isn't impossible, but there are so many OTHER possibilities as well.... like a plain ordinary leak elsewhere, in a part they DID touch. I had intended to look in the reservoir, but I was steaming hot about the problem, needed to unload a bunch of newly acquired tools from the truck, and plain-out forgot to.

I am also not a believer in 'throwing parts at a problem"..... you figure out what it has to be, you fix what you KNOW is wrong, and you verify that it is right after the fix. Cheaper that way, AND you actually fix it....

No I am not "debating", it is laying out facts as they come up, and trying to get an outside check....

vpt
09-11-2011, 10:58 AM
Thanks guys. I guess I've been successfully repairing cars & trucks for the past 45-50 years, not knowing what I'm doing.

I'm so glad to have found a forum where people who have never worked on cars or trucks professionally know so much more than I do.

I tried to help. Help isn't appreciated.....unless you're being charged an outrageous sum of money...My bad, I offered my experience for free.




I have to apologize as well, going back and reading again it seems I came across a little harsh. That happens sometimes when I spend to much time on the internet going from forum to forum. My frustration from one forum will bleed over to the next some times.

I just have to say though I used to push fluid back into the system from the calipers for years as well. I have noticed over the years though that I have been replacing more master cylinders then I thought I should have. I went to school for automotive about 17 years ago and was taught to never push fluid back into the reservoir because of contamination. I was young and didn't think much of it and it is easier to just push the fluid back instead of breaking all the bleeders free and then pushing the caliper pistons back in for new pads. Well after wising up I started doing the extra work of breaking the bleeders free and making sure no fluid ever got pushed back into the master I have been having much much better luck with the master cylinders lasting.

The deal is the further down the brake system you go the dirtier and more contaminated the fluid is. In the calipers you have burnt and contaminated with small chunks of rust and dirt fluid. When you push that fluid back up threw the system the particles get hung up and cause problems with small ports/orifices and valves, seals, etc. causing problems and extra wear on parts.

When replacing pads or doing any brake work the bleeders should be broke free and then the pistons compressed. After all the work is done I suck out all the old fluid in the master and then fill with new. I put a clear hose on each bleeder and bleed one at a time until I see the new clear fluid coming threw the hose. Typically you start with the furthest caliper/slave first but on some vehicles like say honda cars the way the prop valve works you have to bleed diagonally (rear passenger side then front drivers side). the bleeder is always at the highest point in the caliper fluid cavity, that is how the air is removed. The brake line running to the caliper many times is in the middle of the caliper cavity and pushing the fluid backwards won't evacuate the air trapped at the top of the cavity.

The fluid itself can make brakes feel like junk. Brake fade is a common term around the race track and is what happens when you boil the brake fluid. Boiled fluid will make the brakes almost useless even thought the rest of the system is in perfect working order. So it pays to have good fresh clean fluid in your brake system all the time! I take care of a fleet of trucks and if any of them need brake work and the fluid is over a year old I will flush the system, even without doing any other work a fluid flush will make the brakes feel much better! (Same goes for power steering ;) )

Now saltmine you mentioned about letting off the peddle and the fluid flowing backwards into the master. The brake system is a open hydraulic system until you push on the peddle at which time the piston in the master goes past the port(s) to the reservoir closing off the only open path which then starts applying pressure on the caliper pistons and/or wheel cylinders. When you let off the peddle the pressure drops as the piston in the master moves back, when the piston moves all the way back it opens the ports to the reservoir again and the system is open once again. Even with ABS the system is open from reservoir to caliper until the ABS system is activated. When the ABS system is activated it is actually shutting off the brakes (stopping the fluid from master to caliper).


Since I started breaking bleeders free and only flowing the fluid out the calipers I have had much much better luck with master cylinders, prop valves, load valves, and ABS systems. (should have listened to my teacher better right off the bat) In fact I believe we have two trucks with over 300K miles with their original masters. Before I would be replacing masters every 150-200K.


So, I am not telling you how to bleed your brakes, do whatever you like and what works for you. I am just suggesting to try bleeding the fluid out the bleeders like I was taught.

Sure I don't have 45-50 years under my belt. But I do have 3 years of school and 15+ years of taking care of extreme duty vehicles with a passion for excellence (sounds like a marketing ploy). So sought after in fact that I have had people come from surrounding states and stay over night or for the weekend in hotels just to have me do work on their vehicles (no joke).

Take my advise however you want, just no hard feelings, we are all here to learn. ;)

A.K. Boomer
09-11-2011, 11:00 AM
DOT5 is a long term fluid ..it does not degrade like other fluids, can be left in for many years ..break systems filled with DOT5 will last a lot longer than filled with 3 and 4..no water means no rust and little wear.



All the best.markj


Dot 5 can be a big mistake - it may last longer but your brake system may not, it cannot absorb moisture - it can leave pockets of water in the system and they in turn can attack the bores of both master and slave parts - there really is no "huge" advantage to it - it has a marginally better boiling point, One really can't make the claim that it can be left in allot longer due to the fact that it cannot absorb moisture, in many cases it turns out to cause problems not cure them.

You want to take good care of your brake system then flush it with high quality dot 4 once in awhile - that's all it takes - brake and clutch fluids are about the most neglected thing on the planet yet its surprising they do so well,
Iv seen vehicles over a couple decades old with over 400,000 miles on the original dot 3 brake and clutch fluid without a problem - it's good stuff, and its surprising at how much neglect it takes while still protecting the components. all you have to do is dump it once in awhile.

A.K. Boomer
09-11-2011, 11:18 AM
I won't get into it with the brake system as it's got ABS and I don't know it due to being Japanese,

but the clutch system is easy multiple choice --- you either have a bad slave or a bad master,

your slave can be bad in one of two ways - the seal (or bad bore) can either be allowing fluid past and this is the most easy diagnosis there is - cuz it will show up on your garage floor, if it's not then the seal can be allowing air back in when you release the master - then the next compression is "lame"
Also keep in mind that many of the internal slaves have long bleeders to get to the slaves - some of these bleeders sit in a pinned shaft with an o-ring - they wobble around like crazy and can either leak or suck air.

The master can either by-pass fluid back to the reservoir or suck air also - it can also be adjustable and the intake port not being uncovered for the next charge,

to test the bores in both the master and the slave run the engine in neutral and place your foot on the master and depress very slowly like one inch per 5 seconds till you reach the bottom - then try for a syncro'ed gear like first or second and see if it falls in.

aboard_epsilon
09-11-2011, 05:48 PM
Dot 5 can be a big mistake - it may last longer but your brake system may not, it cannot absorb moisture - it can leave pockets of water in the system and they in turn can attack the bores of both master and slave parts - there really is no "huge" advantage to it - it has a marginally better boiling point, One really can't make the claim that it can be left in allot longer due to the fact that it cannot absorb moisture, in many cases it turns out to cause problems not cure them.

You want to take good care of your brake system then flush it with high quality dot 4 once in awhile - that's all it takes - brake and clutch fluids are about the most neglected thing on the planet yet its surprising they do so well,
Iv seen vehicles over a couple decades old with over 400,000 miles on the original dot 3 brake and clutch fluid without a problem - it's good stuff, and its surprising at how much neglect it takes while still protecting the components. all you have to do is dump it once in awhile.

i thought hydroscobic means it actively absorbs water ....meaning that the water does not get there by accident ..the dot 3 and 4 brake fluid pulls it in ..absorbs it,out of the air, because that's its nature..

with silicone ..hopefully you wont have any water in the lines ..no globlets nothing..unless put there.

all the best.markj

Iraiam
09-11-2011, 06:26 PM
I haven't installed DOT5 in anything, mainly because I have never ran across anything that required it.

I have read in a few places that if you convert a brake system from DOT3 or 4 to DOT5 fluid, you must disassemble and clean out ALL of the old fluid because even a small amount of the old fluid can contaminate the DOT5, and it can turn into a gel.

I also understand that DOT5 is at least somewhat compressible, a property which seems undesirable in a hydraulic brake system?

Water (moisture) is everywhere and gets into everything, if it is absorbed into solution you have a way to easily get rid of it by changing the fluid.

John Stevenson
09-11-2011, 07:56 PM
Just something in passing.
When we had the truck garage only smaller truck had hydraulic brakes, most were air brakes but all clutches were hydraulic, except Bedford GM which were still rod operated { worked OK though }

We had two systems Girling and Lockheed, Girling was never no problem as they had a positive valve on the end of the cylinder to close the reservoir off when the pedal was depressed.

The Lockheed OTOH were a pain in the backside as when bleeding because you had no pressure half the fluid went back into the reservoir.
You could spend an hour and still not get a pedal.

In the end we found out that if we drained the whole system, got a pump oil can full of fluid and fed it from the slave cylinder so it back filled until the reservoir was full, when we closed the bleed screw off we would have a pedal.

If the pedal wasn't decent we sucked some out the reservoir and carried on. If you were stupid enough to think that now it was full it would bleed you lost the pedal and had to start all over again.

Fortunately only a few trucks had Lockheed systems, most had Girling.

Don't know if it's relevant but it worked for us, mind you this was in the days when you could buy cylinder rubbers in boxes of 20, don't suppose they sell repair kits any more ?

J. Randall
09-12-2011, 12:09 AM
i thought hydroscobic means it actively absorbs water ....meaning that the water does not get there by accident ..the dot 3 and 4 brake fluid pulls it in ..absorbs it,out of the air, because that's its nature..

with silicone ..hopefully you wont have any water in the lines ..no globlets nothing..unless put there.

all the best.markj

Aboard, what you are describing is hygroscopic, and yes old brake fluid of the Dot 3 and 4 varieties are notorious for it.
James

tdmidget
09-12-2011, 12:29 AM
I have to apologize as well, going back and reading again it seems I came across a little harsh. That happens sometimes when I spend to much time on the internet going from forum to forum. My frustration from one forum will bleed over to the next some times.

I just have to say though I used to push fluid back into the system from the calipers for years as well. I have noticed over the years though that I have been replacing more master cylinders then I thought I should have. I went to school for automotive about 17 years ago and was taught to never push fluid back into the reservoir because of contamination. I was young and didn't think much of it and it is easier to just push the fluid back instead of breaking all the bleeders free and then pushing the caliper pistons back in for new pads. Well after wising up I started doing the extra work of breaking the bleeders free and making sure no fluid ever got pushed back into the master I have been having much much better luck with the master cylinders lasting.

The deal is the further down the brake system you go the dirtier and more contaminated the fluid is. In the calipers you have burnt and contaminated with small chunks of rust and dirt fluid. When you push that fluid back up threw the system the particles get hung up and cause problems with small ports/orifices and valves, seals, etc. causing problems and extra wear on parts.

When replacing pads or doing any brake work the bleeders should be broke free and then the pistons compressed. After all the work is done I suck out all the old fluid in the master and then fill with new. I put a clear hose on each bleeder and bleed one at a time until I see the new clear fluid coming threw the hose. Typically you start with the furthest caliper/slave first but on some vehicles like say honda cars the way the prop valve works you have to bleed diagonally (rear passenger side then front drivers side). the bleeder is always at the highest point in the caliper fluid cavity, that is how the air is removed. The brake line running to the caliper many times is in the middle of the caliper cavity and pushing the fluid backwards won't evacuate the air trapped at the top of the cavity.

The fluid itself can make brakes feel like junk. Brake fade is a common term around the race track and is what happens when you boil the brake fluid. Boiled fluid will make the brakes almost useless even thought the rest of the system is in perfect working order. So it pays to have good fresh clean fluid in your brake system all the time! I take care of a fleet of trucks and if any of them need brake work and the fluid is over a year old I will flush the system, even without doing any other work a fluid flush will make the brakes feel much better! (Same goes for power steering ;) )

Now saltmine you mentioned about letting off the peddle and the fluid flowing backwards into the master. The brake system is a open hydraulic system until you push on the peddle at which time the piston in the master goes past the port(s) to the reservoir closing off the only open path which then starts applying pressure on the caliper pistons and/or wheel cylinders. When you let off the peddle the pressure drops as the piston in the master moves back, when the piston moves all the way back it opens the ports to the reservoir again and the system is open once again. Even with ABS the system is open from reservoir to caliper until the ABS system is activated. When the ABS system is activated it is actually shutting off the brakes (stopping the fluid from master to caliper).


Since I started breaking bleeders free and only flowing the fluid out the calipers I have had much much better luck with master cylinders, prop valves, load valves, and ABS systems. (should have listened to my teacher better right off the bat) In fact I believe we have two trucks with over 300K miles with their original masters. Before I would be replacing masters every 150-200K.


So, I am not telling you how to bleed your brakes, do whatever you like and what works for you. I am just suggesting to try bleeding the fluid out the bleeders like I was taught.

Sure I don't have 45-50 years under my belt. But I do have 3 years of school and 15+ years of taking care of extreme duty vehicles with a passion for excellence (sounds like a marketing ploy). So sought after in fact that I have had people come from surrounding states and stay over night or for the weekend in hotels just to have me do work on their vehicles (no joke).

Take my advise however you want, just no hard feelings, we are all here to learn. ;)

+1 Do your brake/clutch work, then open the bleed screws. Add clean fluid to the master cylinder. When clean fluid is dripping out the screws that's as good as it gets. Takes about 2 beers to bleed the whole thing. No screaming, argueing, pumping, and no dirty fluid left in the system.

J Tiers
09-12-2011, 09:33 AM
Aboard, what you are describing is hygroscopic, and yes old brake fluid of the Dot 3 and 4 varieties are notorious for it.
James

Which would be why the clutch reservoir cover is an air-tight sealed cap.

Ditto brake fluid

aboard_epsilon
09-12-2011, 09:39 AM
Which would be why the clutch reservoir cover is an air-tight sealed cap.

Ditto brake fluid
it cant be air tight ..it has to have a breather ..to allow for expansion ..

there will be a pin hole usually right in the middle of the cap

the barrier between the outside air and the fluid is usually a loose fitting rubber diaphragm that floats on the fluid ..

just a thought

maybe all the gen on the moisture getting in the fluid was pre rubber diaphragm days ...and this has stuck...maybe it doesn't happen as much now .


all the best.markj

A.K. Boomer
09-12-2011, 10:00 AM
Water (moisture) is everywhere and gets into everything, if it is absorbed into solution you have a way to easily get rid of it by changing the fluid.



Yup - and like previously stated it gets dispersed instead of forming a pocket of pure water that will then have its way at the bottom of a cast iron bore immediately and an aluminum one after a bit.

It's true dot 3 and 4 are moisture hungry - its why you seal the cap tightly back on the brake fluid container when shelving it - if you find that it was loose you should throw it away...

I am pretty partial to conventional due to the results that iv seen as I don't believe they could get any better esp. considering the neglect that's related to these systems BUT --- I have to admit I live in a low humidity state and can remember when I lived back east and all the trouble back there with wheel cylinders and such STILL - don't have a track record of how much better OR worse they would have been if they were using dot 5, all im saying is it's totally not needed out here because you can't fix something that isn't broken...

A.K. Boomer
09-12-2011, 10:07 AM
it cant be air tight ..it has to have a breather ..to allow for expansion ..

.


all the best.markj


Totally depends --- some are actually 100% airtight - they have a rippled bellows style diaphragm that is a total seal - it expands enough to drain a reservoir - this is sufficient enough to allow for total brake pad wear from new to totally worn out, self adjusting drums don't require extra fluid from the reservoir as they wear - but all disc bakes do...

M_C
09-12-2011, 10:16 PM
Aboard, what you are describing is hygroscopic, and yes old brake fluid of the Dot 3 and 4 varieties are notorious for it.
James

They're designed to be hygroscopic.
If it wasn't needed, manufacturers could quite easily use any of a wide variety of oils. Main reason for DOT 3, 4 or 5.1 being used, is to absorb any moisture that may get into the system.

It's far safer to have a fluid that the boiling point gradually reduces on during it's service life, than a fluid where any moisture would gradually migrate to the lowest point of the system and cause a pocket of fluid with a much reduced boiling point.


If brake system's were to be designed from scratch now, I suspect we wouldn't be using conventional DOT fluids, but given fly by wire braking isn't that far of in the distant future, I suspect manufacturer's don't want to go to the hassle/expense of redesigning proven systems.

J Tiers
09-12-2011, 10:34 PM
Clutch is a sealing type rubber cap.

Brake fluid is a regular cap, probably with breather, but not a very big one.

vpt
09-12-2011, 10:42 PM
If brake system's were to be designed from scratch now, I suspect we wouldn't be using conventional DOT fluids, but given fly by wire braking isn't that far of in the distant future, I suspect manufacturer's don't want to go to the hassle/expense of redesigning proven systems.



They are working on stuff. The most interesting I seen was a ford system where each wheel had it own electric motor/generator/electronic brake/electronic ABS and traction control/etc.

With a electric motor on each wheel each wheel can act totally independent of the others in either acceleration, charging, braking. Much like the hybrids the electric motors would drive the car and on decel charge the batteries and also can be electronically brake each wheel. Pretty much no drivetrain in the car so it can be used for all passenger and cargo space and battery/fuel cell space. Light weight all time all wheel drive and the wheels could turn 180 degrees for parking because there are no drive axles to limit turning. Neat stuff.

J Tiers
09-13-2011, 12:04 AM
Lots of people can fix hydraulics. Not so many can fix complex electric systems, many mechanics are totally "at sea" with very simple electrical problems.

And even those who can, will be limited by availability (or not) of replacement parts.

Since the electronic assemblies WILL be made in china...... and the chinese DO NOT SELL PARTS.... you will have to replace the assembly with an identical one, assuming they are available.

Most likely, ONLY the whole "cartridge axle" will be available, at a guess, a $2700 to $4500 part, minimum. (Cost to the auto manufacturer, $750, cost OF manufacture in china, $250)

No parts? Toss the car. Liability for "inferior substitute" parts would be astronomical and open-ended (although the chinese' liability for defective parts will be zero.....).

Yah, bad attittude, whatever.

aboard_epsilon
09-13-2011, 07:16 AM
They're designed to be hygroscopic.
If it wasn't needed, manufacturers could quite easily use any of a wide variety of oils. Main reason for DOT 3, 4 or 5.1 being used, is to absorb any moisture that may get into the system.

It's far safer to have a fluid that the boiling point gradually reduces on during it's service life, than a fluid where any moisture would gradually migrate to the lowest point of the system and cause a pocket of fluid with a much reduced boiling point.


If brake system's were to be designed from scratch now, I suspect we wouldn't be using conventional DOT fluids, but given fly by wire braking isn't that far of in the distant future, I suspect manufacturer's don't want to go to the hassle/expense of redesigning proven systems.

Don't know.

I changed out all the dot 4 on my triumph stag 22 years ago ....put in silicone brake fluid.

This was done after reading 10's of articles in classic car magazines ..saying it's the thing to do ..to preserve the braking system, during long periods of lay-up.

So now, the cars not been used in the last 20 years ..it's stuck in my back garden.........one day, i will put it back on the road, i will use it. ..we will see then ..if the mags were right.

All the best.markj

vpt
09-13-2011, 08:53 AM
Lots of people can fix hydraulics. Not so many can fix complex electric systems, many mechanics are totally "at sea" with very simple electrical problems.

And even those who can, will be limited by availability (or not) of replacement parts.

Since the electronic assemblies WILL be made in china...... and the chinese DO NOT SELL PARTS.... you will have to replace the assembly with an identical one, assuming they are available.

Most likely, ONLY the whole "cartridge axle" will be available, at a guess, a $2700 to $4500 part, minimum. (Cost to the auto manufacturer, $750, cost OF manufacture in china, $250)

No parts? Toss the car. Liability for "inferior substitute" parts would be astronomical and open-ended (although the chinese' liability for defective parts will be zero.....).

Yah, bad attittude, whatever.



That is true especially right away. I can see only being able to get the whole assembly or nothing for quite some time. Thats also the reason I don't buy brand new vehicles, they are expensive to fix! lol

J Tiers
09-14-2011, 12:26 AM
Shop has decided they installed a bad clutch slave cylinder......

They must be convinced, since they will have to pull the tranny (again) to replace it, and this boy ain't payin a SECOND time......

They are going to look for evidence of fluid soaking into the clutch face as well..... probably not, there isn't a lot of fluid IN the thing, and there is some room in the bell housing.

No word on the brakes, but they agree the prime issue must be regular brakes, the ABS is indicating as a consequence.

nort
09-14-2011, 08:55 AM
I would like to start off my first post ever by introducing myself. I am employed as a mechanic and have been for long time. I dont specialize in any one field but am faced with different jobs everyday. I have had a Ford ranger I bought used in 1996 3.0 v-6 5-speed manual trans. Currently 265 thousand miles on odo. Has been hard to shift into first and reverse off and on. Bled clutch over and over. Other day was looking at tubal canes stuff on u tube and came across a video produced by a large clutch part provider on the proper way to bleed a ford ranger master cylinder and attached line. Very simple to do if you have the whole unit remove from vehicle. You string the reservoir at the top and the hose verticle on a post or wall. The problem with bleeding on the vehicle is the routing of the hose. Air gets in a horizontal section and is very hard to force out the bottom. Also, the mounting angle of the master cyl. ads to the problem. I dont want to whip a dead horse here on my first post but I felt I had to because this has been an ongoing problem on my own truck. I feel for the mechanics who run into this seemingly simple job and it comes back on them.

J Tiers
09-14-2011, 09:10 AM
Nort.... it is not any too practical to bleed an S10 clutch off the vehicle..... the slave is buried inside the bell housing.

Besides, all the bleeding in the world won't help a leaky slave that pulls down the reservoir until it slurps air. I don't KNOW that is it, I forgot to look in the reservoir when I took it in, but it makes sense... took 30 days to pull it down, then first intermittently sucked air, finally ran out of fluid entirely.

It's their problem, they own the bad cylinder, I own the new one they will be putting in if that wa the problem.

vpt
09-14-2011, 09:54 AM
Many ford hydro clutches are self bleeding. Meaning the fluid line going into the slave is at the top of the cavity, the master pushes enough fluid that when you let off the peddle it back flows enough to clear air out of the line. So pretty much fill and keep pumping till you have a good peddle and no more air bubbles pop up in the master.

nort
09-14-2011, 10:08 AM
Yes J.tiers, as my dad used to say, it will all come out in the wash. The video on the ford clutch is for bleeding a new master with line attached if you watch the whole thing the unit is shown on a stand with a dial indicator on the pressure plate demonstrating the proper release amount. The slave is bled after installling master cylinder.

A.K. Boomer
09-14-2011, 10:49 AM
Has been hard to shift into first and reverse off and on. Bled clutch over and over. .



Just a quick note and not anything against what you wrote but using this opportunity to shed light in a different area and incidentally also know this is not JT's problem either ------ BUT --------------------------------------------------------
if a manual transmission is having a tough time going into first or reverse or any other gear for that matter there are also two other things that can be effecting this function that not everyone thinks about - the first is the more obvious trashed pilot bearing - the second is the often overlooked totally dry clutch splines,,, they need assembly grease or they simply will not release - this will keep gears from shifting smooth - it will also wear out one side of the clutch disc more that the other, even vehicles with proper assembly lube will run dry eventually --- if you have access shine a light up in the bellhousing and look for the dreaded "red rust" between the clutch splines and the trans shaft - when you see that you know things are sticking --- you can avoid a tear-down by directing the nossel of some good moly spray and let soak and repeat - then seal it off with some LPS-3...

vpt
09-14-2011, 03:45 PM
And warped flywheels or pressure plates. Bent fingers on the pressure plate, springs came out of clutch disc. Depending on the style the clutch fork could be bent.

Ever see a flywheel shear the crank bolts off or the starter ring fall off the flywheel?

nort
09-14-2011, 10:03 PM
I understand what you are trying to say boomer, internal trans. parts come unglued and will cause hard shifting. I changed my throwout bearing, master cylinder clutch disc, and pressure plate myself on my ranger, at that time the splines and the pilot bearing were checked and were in excellent condition. I bled the clutch by myself and didnt have too much trouble with gravity and just pumping it up. After all that the clutch released beautifully. Two weeks later, it started to get hard to get into 1st and reverse. That when I started wondering if it could be faulty components or internal trans. parts. I happened to see clutch bleeding vid. by shear accident poking around u tube. I agree with j. tiers, the ball is now in whoever is trying to fix this problems court, but I really doubt that the T.O. unit is bypassing but not leaking fluid. I pulled a ten speed fuller trans. out of a truck that had sheared the fly wheel bolts and the clutch, flywheel assy. came out on the trans. input shaft. It was a 68 freightliner cabover and I was using a jib mounted I beam hoist that was bolted to a 8 inch wooden beam in the shop. The hoist sagged and the I beam twisted or it might have collapsed all together. That was a little too close. Twin disc clutch with heavy pot type flywheel.