Brake lathes

[Guido]

Been a long time since I hired anyone to do a brake job, but every brake job always seemed to require

[Doozer]

"New rotors are made on a CNC lathe.
They are so accurate, they never need turning."

Auto parts guy said to me.
I just smiled, and said thank you for the tip.
Make perfect sense to me.
...If I had a frontal lobotomy!

-D

[Joe Rogers]

My shops brake lathe is sitting idle most of the time now. I know that I haven't turned a rotor on my own car in over 10 years. New rotors are too cheap. My time is too expensive even though it's free to me. Too many comebacks turning rotors to fix pulsations. New rotor design cuts so much structure out of the rotor design to save weight the parts are unusable half way through a set of pads. The factory insists that warranty repairs to O.E. rotors be attempted. The lathe gets used then.
Joe

[hermetic]

If you look at this problem from a purely engineering viewpoint The engine in your car uses petrol (gas) to generate heat to produce forward motion, it is the job of the brakes to convert the forward motion back in to heat, and dissipate it. You get two kinds of problems with drums and discs, scoring and warping. Scoring is usually caused by running the shoes/pads to low, or a trapped stone etc warping is caused by the disc or drum not being able to dissipate the heat fast enough, and warping as a result, this produces the pulsing effect felt at the pedal. If you then remove metal from the drum or disc, to correct the warpage, you actually make it LESS able to dissipate the heat, and it will quickly warp again. Replacement discs are now SO cheap that it is doubly pointless to do it! Brake lathes were sold to garages (and as franchises) as a money spinner, which never actually delivered.
Phil

[old mart]

Since they did away with asbestos based disc pads, I have found that the discs are at or near the wear limits when the pads are worn out. I bought Brembo discs and pads together for only about 1/3 more than the pads alone.

[mars-red]

For a lot of cars, you can get discs so cheap that I can understand why having old ones turned is less popular (as far as turning brand new ones, I had no idea that was ever common practice). There's one place left fairly close to here that will still turn rotors. I recently had them turn the front rotors that were on my wife's Flex because they had warped a bit. In this case, new rotors were about $60 each so it was a lot cheaper to have them turned and get some more use out of them. Up until a couple years ago my daily driver was a '91 Golf (with brakes and wheel hubs from a later generation Golf), and brakes for that were so cheap that it made no sense to have old ones turned to get more use from them. I ran slotted rotors on it for the last few years I had it, and no place will turn those anyway.

I've thought about picking up a used on-car brake lathe before, it's tempting with so many deals on CL.

[CarlByrns]

Brake lathes were sold to garages (and as franchises) as a money spinner, which never actually delivered.

Wrong. In the olden days rotors and drums had a lot more material on them- they were engineered to be resurfaced. Brake heat, road salt, cold water splash can do number on the braking surface which could be machined off. The minimum thickness was always stamped on the drum or rotor.

Starting in the 1970's as a cost-cutting move, many car companies started equipping their products with rotors/drums that were at min. thickness when new. Honda was the exception and (the last I knew) still insists that new front rotors should be turned with a knuckle-mounted 'on-the-car' brake lathe which assures the rotor is parallel and perpendicular to the centerline of the hub.

[Willy]

My experience pretty well echos Carl's.
Brake system components had mass for heat dissipation and could be turned several times before needing replacement. Other than trucks designed for towing most cars don't have that option anymore.
With an emphasis on fuel mileage and handling combined with cost cutting and weight savings, many cars just can't take advantage of the benefits offered by these tools.

Another major factor is the dwindling number of folks that seek out these services is that we now live in a disposable society. We are as a whole are more accustomed to replacement than repair.

Personally when doing a proper, "factory new" brake job on a disc/drum equipped car I find you can't beat the quality that turned rotors, drums and arcing the shoes deliver.

Reminds me of another lost service...the shoe repair man.

[Doc Nickel]

I had a brake lathe for a while, hoping to augment my job-shop with easy-to-do stuff.

I had it something like six years, used it twice, sold it at a heavy loss.

Yes, there used to be a major and regular demand for brake lathes and turning rotors and drums, but at least three things have changed all that in the last 10 to 15 years.

One, the general design is better. Modern brakes and brake materials make them last longer, the lighter cars caused by the attempts at better fuel efficiency puts less of a strain on them, and anti-lock brakes and computer anti-spin controls help distribute the braking power better. The systems just generally last longer.

The flip side of that is number two- as noted above, the components are made lighter, and have less metal to turn off. They're rarely made "already at minimums", but they are made thinner, with less metal to go before minimum, so when it would in the past have been time to turn the rotor, it's now time to replace it.

That's done as part cost-cutting (less material used) and the aforementioned weight reduction.

And to go with both of those is number three- we're now getting most of our iron brake components from China. That has drastically reduced the cost of those components- in 2000, I rebuilt a big Oldsmobile, and had to scrounge junkyards for turnable rotors, as new replacements were $125 each. I can now buy imported rotors for $35.

For many shops, it's become cheaper to replace the drum or rotor than it would be to pay a tech to turn it. Couple that with the fact the newer rotors don't always have enough left to turn, and yeah, there's been a huge drop-off in the need for brake lathes.

Other aspects that go with it: A lot of small and mom-and-pop garages are and have been closing, generally losing out to chains like Midas or Quiklube, or chain stores like Sears and Wal-Mart. Many of those places don't even have a brake lathe- not only because of the above reasons, but also because they have a hard time hiring competent people to run them.

Also, many, if not most, chain auto-parts stores, like NAPA, Pep Boys, CarQuest and AutoZone, offer rotor, drum and flywheel turning as a service- and also dirt cheap. The local Schucks/O'Reillys will turn a rotor for $15. These places generally have newer, computerized machines that do the work automatically- for the same 'competent employee' issues as above.

And since the machines have always been reasonably well built, and even worn ones still able to cut surprisingly true just due to the nature of the design, they last a long time. All of which has led to a glut of the machines.

I had an Ammco 2000, I think it was, in top shape, with some fairly complete tooling. I literally couldn't give it away. I finally gave it back to the guy I'd bought it from and ate the cost, just to clear up some space in the shop.

My local Craigslist virtually always has three to five brake lathes listed- some for absurd, near-new prices, others for get-it-out-of-my-shop prices. The local secondhand shop has a complete one, an older model, but complete with cabinet and tooling, and the guy that runs the place has told me no one even asks about it.

It would be nice if there was some way to convert them into something useful, but the design is just too specialized. I'd considered trying to turn mine into some sort of second-op lathe or speed lathe, but I figured by the time I did so, I'd have more into it than buying a real speed lathe, and it still wouldn't be all that useful.

Doc.

[Doc Nickel]

Another one, in the same vein, is valve grinding machines.

Simply put, virtually no one grinds valves anymore- better metallurgy and hardened seats have greatly increased the longevity of the parts in the first place, but also there are way fewer people that bother rebuilding engines anymore. Generally speaking, if a modern car gets to the point where it needs the valves serviced, it's well and truly clapped out, and would be cheaper to junk it and buy a used car than have the work done.

And again, the older machines are built well enough that most have easily survived- I have one built in the late 40s that's still in great shape.

So there's a glut of those too. I have a Sioux, with a cabinet, that's complete with lots of stones, guides and accessories, and the last time I put it up for sale (asking maybe $600, which is less than I paid) I got exactly zero calls. I shopped it around to some of the local repair shops, and none were even remotely interested. Several had multiples that they already didn't use.

It's a pity, one hates to see good, working machinery go to waste for lack of use, but the same thing happened to the anvil industry when the automobile ended to need for every family to have a set of farrier equipment.

Doc.

[Spin Doctor]

If I have to do brakes on one of my vehicles I want the pads and rotors thete on hand before I even start. I want to get the car up on jack stands, the job done and the car on the ground in the minimum time possible while doing it properly. I'm not going to take the time to run to NAPA, get the rotors turned. The last car I did was a Chrysler 300 for my daughter (wife's car). Over 100k miles on the car before the fronts needed to be touched. Did the backs about 6k miles later. For that many miles on a set of brakes I'll eat the cost of a new set of rotors

[lakeside53]

New rotors for my truck, and roughly the same for the car.... $24 each. I'm sure they are Chinese made, but they are 100% guaranteed by O'Reilly's or Car Quest so I could care less where are made. Cost turn the old (if they can be..) $14 each. Not worth it. The new work fine out of the box. I've done about 10 brake jobs on various cars/trucks in the past few years., every time, new rotors, no issues.

[JoeLee]

A friend called ma a month ago asking who would turn rotors as he couldn't find a shop that even had a brake lathe. I told him it's a thing of the past, this is a throw away world and it's probably cheaper to buy a new set.

JL....................

[vpt]

Brake lathes are only good for used car lots now days.

Many used car dealers are learning that is a cheap way to get away with skipping a brake rebuild. Get a car/suv/truck in with pulsing brakes just turn all the rotors and put it on the lot.

[projectnut]

Another thing that hasn't been mentioned (I could have missed it) is that some rotors can't be turned because they're only case hardened. If they do warp you'd have to turn them down past the hardened shell to get them true. They'd last about 2 stops before warping again.