View Full Version : OT: Death of a Lucas CAV IP and Cleaning algae out of a diesel tank

Jon Heron
08-21-2014, 03:39 PM
Go figure, the only diesel that I have not run biodiesel in *yet*, has had a major fuel failure.
The cummins 4B on my zoomboom seems to have grown algae in the diesel fuel, it clogged my IP pump and sheered off the shaft.
The new hydraulic head, rotor and 4 new injectors (they were cheap) are on the way and I intend to clean the crud out of my tank before I attempt to rebuild the pump.
Does anybody know of an easy way to break up and remove this terrible sludge from the tank?
Carb cleaner works to clean it out of the IP but that is not practical in the big tank. I was thinking maybe acetone or maybe a mix of methanol and caustic might break it up? Anybody ever dealt with this before?
Here is inside of the tank, it has about 3/4" to 1" of black/brown sludge in it.
There is even some gravel in there lol... :rolleyes:
Here is some of the sludge I scraped out.

Any suggestions here would be appreciated, in the mean time I will continue to scrape out the crap...

Jon Heron
08-21-2014, 03:40 PM
Here are some shots of my poor IP if your interested;
I know it looks like rust but it is not, it is a slimy greasy crud, it washes off pretty well with carb cleaner, biodiesel does not touch it.
\ http://theherons.ca/album/var/albums/Jonnys_Stuff/forklift/IP/IMG_20140729_171537.jpg?m=1408647773
Here you can see the broken rotor shaft in the hydraulic head, I tried to beat ti out with a drift and 5lb mash with out it moving lol
This the the pumping element where you can see the other end of the broken shaft:

08-21-2014, 05:05 PM
have you tried gas? Many don't like to use it but I will on occasion for things like this if it works. Otherwise "gun cleaner" for paint guns/lacquer thinner works wonders too. Sludge sucks, I am sure every piece will have to be disassembled for a good cleaning.

Unless maybe an ultra sonic cleaning would work? Supposedly it cleans insides of injectors. I know a small ultra sonic cleaner can be bought for under $40-50 from walmart or such.

Good luck with it, I'll be watching to see how it works out for you. Did this motor/fuel sit for a long time? Or just a bad batch?

08-21-2014, 06:54 PM
wow Jon you really do get all the best jobs, don't you?!

as the sludge is biological, you could try NaOH (lye) and SDS if you can get your hands on some, that'll blow up and dissolve those cells/ proteins in no time. Perhaps add some engine degreaser too, that helps everything I've ever added it too (makes a great stink bug killer concoction).

Jon Heron
08-21-2014, 09:31 PM
Andy, Apparently the algae grows at the water diesel interface then falls to the bottom making the sludge. I only run this thing a dozen or so times a year so I guess that was enough time for it to grow in the IP...
Matt, yeh, I am a WINNER!! :cool: lol
When I get back on Sunday I think I will try some caustic and methanol or even caustic and water on a sample of it and see what happens...

08-22-2014, 07:18 AM
This is a frightening thread. Wow! I have heard of bacteria in Kerosene and we used to drain our rocket heaters completely and all fuel had to be filtered when filling. Byproduct was a 'fuzz' like stuff that plugged the filters and water that rusted the fuel tank. Big pita.
I did a quick search as I have never seen this with diesel. Sounds like it could be both fungus and re-combination of wax, paraffin, asphalt.



I'm struggling with why your fuel filter didn't pick this stuff out before it went to your IP.

fuel tank cleaner-


Reading the MSDS looks like naptha and dioxaborinanes which is mostly methylene. Sounds like you need to cut it (reduce) with something lighter.

Jon Heron
08-22-2014, 10:23 AM
Thanks Abner!
It gets into the pump and past the filter as this machine gets very little use, that gives the algae enough time to grow in the IP, lines and everywhere else the fuel is sitting. The spores or whatever starts the algae must be small enough to get past the filters and then any moisture in the fuel allows it to grow, I guess.
What gets me is I was waiting to change the fuel lines and rinse out the tank before I ran biodiesel in her to avoid many plugged filters as the biodiesel usually cleans all the years of pump diesel gunk out when first used.
Now I am wondering if I had just filled it with bio from the start if it would have flushed out the bad pump diesel and bugs with it.... Oh well its spilled milk now...

08-22-2014, 10:47 AM
I have had two boats that grew algae in multiple tanks. Both boats sat for a while in Fort Lauderdale in the summer.
That's a perfect environment for alge growth in diesel fuel. High heat and humidity.
I had them cleaned by a company that uses high pressure pumps to circulate diesel fuel in and out of the tank filtering it through multiple filters down to a few microns.
The material that clings to the walls of the tanks is removed by the high pressure return stream from the end of a flexible hose that flops around inside the tank.
I lost about 20% of the fuel in the tanks from the filtering but the remaining fuel was crystal clear and the tank walls were clean.
Maybe you could rig up some sort of pump and filter that would do the job.
Or maybe you could find a company that filters fuel and cleans tanks that way.
I'll bet you are not the only one that has that problem in your area.
By the way, I now use BioBor in my tanks and it really helps.

08-22-2014, 11:05 AM
I've seen a product called 911 for cleaning contaminated tanks. Was your tank steel or plastic because I understand plastic grows algae much more. I have a tractor with 4 year old diesel in twin steel tanks & no algae at all.
I also use an additive in my trucks.

Jon Heron
08-22-2014, 11:26 AM
Its a steel tank with about a 6" square clean out on the top, I have the tank completely removed now so one way or the other it will be spotless when I am done. There is surface rust in the top portion of the tank and the filler neck that I would like to clean off. I am thinking of just brushing it all with naval jelly to remove it but I am worried about it flash rusting afterwords, anybody have any suggestions on how to prevent it from flash rusting? Or maybe I should jest leave the surface rust alone and carry on?
I just tried an experiment of adding 30g of KOH to 1L of warm water on the stir plate and dropped in some goo and nothing, it didn't even fizzle. Next I tried about a cup of NaOH mixed with 700ml of methanol and 300ml of water, bingo that dissolved all the goo into solution leaving it looking like a nice dark ale with sparkling gravel and rust bits at the bottom lol
I have convinced the wife to stay home for the weekend so with any luck I will get this all sorted soon enough...
And yes I have always used Racor biocide in my fuel tanks, just not this one which I had not used biodiesel in yet... DOH! :o

08-22-2014, 12:17 PM
Water problems much?
I'd be looking at my fuel supply. I'm guessing outdoor storage? Lots of snow/ice buildup?

08-22-2014, 02:02 PM
yay! Sodium hydroxide is nasty nasty stuff, kills and dissolves pretty much anything. Including skin, mucosal cells and anodising, in my experience.

Personally I think it's just amazing how organisms can grow pretty much anywhere. Not much consolation I guess Jon, but still a biological wonder.

08-22-2014, 06:28 PM
I bought a used Kubota tractor last fall. Once home, when the temps got lower, I started having problems. I thought I had untreated fuel and it was gelling. Dumped treatment and kerosene in to cut it, and thought I had it licked. Wrong. Of course I changed out the filter which wasn't in the best shape, still choked up and quit. Some on a half way decent day, I pulled the tank which was no easy task. NASTY inside. I drained, flushed, drained, flushed again. I flushed using kerosene, dumped some in, grabbed the tank and swirled it all around as best I could. I got it where it looked fairly clean. The bottom of the tank looked like it has some corrosion, but not but, just surface stuff. replaced the rubber lines, new filter, and so far no problems. I do put in an additive each time I put fuel in, using Power Source, if I recall, comes from Tractor Supply. Supposed to treat, and prevent gelling.

A nasty job for sure!

08-22-2014, 06:36 PM
I really don't like what I'm reading here, makes me feel like starting all my equipment and having empty tanks.
Is your tank is small enough that you can spin it slowly? I have had great success with sand and hex nuts to clean the insides. You can vacuum those out when you get done. Kinda noisy, kinda slow, but it works.

08-22-2014, 06:46 PM
If you've got access to a hot power washer with detergent, that will deal with the worst of the junk in the tank.
Or since you've got the tank off, some good engine degreaser, a good swirl about followed by a rinse out should shift most of it.

Ideally you do want to get the inside of the tank spotless, however it's not always practical. I have previously solved the issue of dirty tanks by adding an extra conglomerator filter (aka water/dirt filter that works by gravity and slowing the fuel flow so dirt drops to the bottom). If it's got a CAV filter head, then there is a version with a bigger glass bowl (about 2" deep) that is ideal for helping to catch dirt/water and monitor just how much is collecting.
That combined with a good dose of fuel treatment usually helps sort things out.

Mike Burch
08-22-2014, 07:07 PM
This stuff does indeed grow on the water/fuel interface. And there will always be at least traces of water under the fuel, from condensation from moist air getting in through the air vent. So the potential for contamination is always there.
When I lived on a yacht, we were refuelling in all sorts of places where the locals regarded fuel hygiene as beneath their dignity, so we never failed to add biocide to the tank every fill. We also regularly drained the bottom of the tank to keep any water to a minimum. This minor effort repaid us with trouble-free motoring.
I don't mean to sound smug, but just to emphasise that keeping diesel is not trouble-proof.

Jon Heron
08-22-2014, 07:23 PM
Good news!
I dumped in 16L of reclaimed methanol along with several handfuls of KOH caustic and the sludge is all gone! Now when I scrape the bottom with the spatula I feel no gum and I see bare metal on the sides of the tank!
After I added it there was an exothermic reaction just like when I make biodiesel, it also made soap that floated to the top like when you overdose the caustic on a batch of biodiesel...
So I am fairly certain I will have a sparking clean tank come morning without the need for much elbow grease...
You can see the soap on top here, looks just like when you make bio lol

08-23-2014, 12:15 PM
A good way to stay away from Algae growth is to keep the tanks full when not in use and always use a biocide in the fuel.
The full tanks eliminates the air which carries the moisture. A constant temperature also helps. Condensation forms with warm air on a cold surface.

Jon Heron
08-23-2014, 02:50 PM
It worked a treat!
I found a couple bullets in there that some nudnik must have tried to shoot through the bottom of the tank, one looks like a .38 and the other looks like a .177 pellet but it is pretty mushroomed to come from an air gun, there may have been more too but they may have come out when I dumped out the water and gravel. This thing must have been parked out in the sticks somewhere where people could tamper with it lol

Jon Heron
09-04-2014, 09:53 PM
She is running like a champ!! :cool:
I was very careful to put everything back together the same as it came apart and it payed off.
It cleaned up pretty good with some lacquer thinner and carb cleaner.


Jon Heron
09-04-2014, 09:54 PM
I used layout dye and a fine machinist square to mark out the adjustment and drive plate positions precisely, though it may look off in the pic it was perfect :)

Jon Heron
09-04-2014, 09:55 PM
Everything I read online said you need special tools for this pump. The guy at the injector shop told me it would either not run at all or would run away and "grenade" the motor... :rolleyes:
Instead of $1500 + HST minimum, I spent about $160 bucks total to rebuild the pump.
Happy happy!

09-04-2014, 09:59 PM
Congrats Jon, looks a hell of a lot better! Staying focused and paying attention to detail always pays off.
Another feather in your cap.

Jon Heron
09-05-2014, 01:24 PM
Thanks Willy!
I must admit, I was pretty impressed when it actually ran as well as before... :p

09-05-2014, 01:29 PM
When I've invested as much time and effort as you have into a project it always runs much better than before.:)

09-05-2014, 06:58 PM
If I knew you were going to rebuild it yourself, I do have a genuine workshop manual for them somewhere.
CAV pumps aren't that complicated, and the basic design was still in use, and even licensed by Bosch, up until emissions finally meant common rail was required.

To rebuild the pump properly so it's exactly on spec, you do need the tools along with a proper test bench, however near enough is often good enough, especially if you're not replacing any critical parts or looking for every last drop of performance.

I only ever deal with them on customers engines, so I only go as far as replacing the top cover. Anything more than that, and it's not worth the risk of something going wrong.

Jon Heron
09-06-2014, 09:23 AM
Thanks for the offer, I managed to find the manual online http://www.solidebolide.nl/downloads/CAV%20Workshop%20Manual%20fuel-injection-pump.pdf
I replaced the most critical part, the head, rotor and pumping element (as well as the metering valve but that's an embarrassing part of the story :o ) the most complicated part though is under the top cover. In the body the only adjustment is the drive plate adjusting ring seen above. Other than that its a simple governor weight assembly and the auto advance plunger all of which were completely seized up with the gum/algae in my pump. What a mess!
It seems there is a lot of information out there that these things operate on black magic and only a fool would open one up to rebuild it at their own peril, this is perpetuated by the injection shops (at least the 2 talked to here) and the internet, but in reality its a simple mechanical pump.
In any event, I wouldn't hesitate to rebuild another one!