Deuce Multi-fuel crankcase full of fuel - please advise over

Hi all, First post. Great forum with lots of excellent knowledge.

My buddy and I are both veterans with some experience operating the M35A2. Friend bought a bobbed truck last year (1970 Kaiser Multi-fuel) and yesterday we were troubleshooting some oil leaks. I happened to check the oil for him, which I had never done before on his truck, and found that the crankcase was grossly overfilled. We pulled the rear pan plug and a full 9 gallons of fuel/oil puked out. Even after this draining, I found the crankcase was still close to operating levels, and it appeared to be almost all fuel.

At this point, I realize that bearing damage is probable, along with accelerated wear of pistons, rings, valve guides and just about every other thing that is oil lubricated. The oil pressure is unknown, since he bought it sight unseen on the web with an inoperative gauge. (Yes, I know). I suspect it is out of limits at idle. I have extensive mechanical experience with aircraft and auto engines, but not much diesel.

Maybe there's hope. The engine starts and runs great, no unusual noises, has good power. Turbo sounds normal and the cooling system is fine. I advised the owner to dump the crankcase, fill with fresh oil, and tow it to a reputable qualified diesel mechanic (or maybe drive it if it's only a few miles). I fear that the fuel pump, the injection pump, or an injector is probably bad and if the problem can be found, and the oil flushed and changed a few times, he may get away without a fried engine. I know these old bitches are tough, but I don't know how long the engine has had this problem or how many miles it's been driven in this condition. I think I may be more worried than the owner, although it's his truck and his money so I want to advise him to choose the correct path. This is a really nicely done Deuce, and it deserves proper treatment.

Two questions:

1. Do any of you have experience with this problem and how was it corrected? Sorry that's two questions.

3. Why is there a rear drain plug on the pan? I'm glad it's there, but why is it there?

I've done a thousand internet searches and searched this site as well. Thanks in advance for all inputs.

Chris

There are several things that can cause this. Search for FDC bypass, flame heater, and injector pump leak pertaining to fuel in the oil. My flame heater got stuck and put a gallon of diesel in my crankcase. I drove probably 60-70 miles before finding it. It doesn't seem to have hurt anything and I hope I'm right. It was about three years ago or so and so far everything is fine.

The most likely cause of your oil contamination is either the hydraulic head o rings have failed, the booster pump seal has failed, and if you have one, the fuel density compensater could be leaking. None of these problems are terribly difficult to fix.

If you have an fdc go ahead and bypass it. You don't need it and it's a common fail point.

To check the hydraulic head o rings you simply remove the shut off cover from the injector pump. Then turn on the master power switch. Look inside where the cover was (you may need a mirror) and look for dripping. If you see any fuel dripping in that cover then the fuel control rod o ring and the 2 o rings under the hydraulic head need replacing.

The booster pump is the hardest one to deal with. It's located on the injector pump right next to the steering box. Which makes it difficult to remove.

To test you simply remove the screws holding into the injector pump. Slide it out as far as you can and turn the master power on and see if fuel drips out.

Years ago I had a buddy who's dad was known to imbibe on occasion. During his "sprees" he would work on an old Ford Galaxie he had in the back yard. He would drain the oil, fill the crankcase with diesel and run the engine until it got warm. He would then drain the diesel out, refill with oil and drive the car around the back roads for a while.
My buddy still has the car and it has that same engine in it and he has restored it and takes it to car shows.
As far as I can tell the diesel treatment hasn't damaged the engine.
One issue with diesel getting into the crankcase is a runaway engine. It happened to me with a 250 Cummins in a wrecker I had. Find the leak immediately and fix it.

The oil pan has 2 drain plugs because there are 2 low spots in the pan. In order to remove all the oil in the pan, both plugs must be removed. Under the Technical Manuals banner, at the top of the page, there are links to the manuals you and your buddy should download.

On the bright side we both got a good crankcase cleaning.

Ha, diesel in the oil isn't that bad. I found the front axle on my dad's truck filled with grease yesterday, not oil. This truck came straight from the Air Force, to GL, to me. I can only imagine that some motorpool sergeant told someone to "Grease the front axle", meaning the hubs and knuckles on this truck, and not knowing any better the poor moron that serviced it went and pumped the housing full of GAA after draining the gear oil.

I wonder how many tubes of grease it takes to fill a deuce axle. I might worry about the differential bearings though.

On the bright side, you (your buddy) has a cleaner engine interior & crankcase. Fix the leak when you find it, keep your eye on the oil level before driving it & you may find no damage other than more than normal oil changes. If you burn used motor oil, filter the drainings & pour them in the fuel tank to reuse. These engines are tougher than we think sometimes. Good luck.

I imagine 6-8 pounds. There was apparently enough residual oil left in there to partially liquefy the grease.

Then only place that fuel is on one side of an o-ring and oil on the other is the hydraulic head.
Remove and by-pass the FDC.
5 minute job.
Had same problem.
MHassett

Thank you all for the inputs and suggestions. Will begin troubleshooting and let you know what we find. Hoping to eliminate these things first. I've searched extensively in the repair manuals and can't find a troubleshooting guide for oil contamination.

Chris

welldigger said:

The most likely cause of your oil contamination is either the hydraulic head o rings have failed, the booster pump seal has failed, and if you have one, the fuel density compensater could be leaking. None of these problems are terribly difficult to fix.

If you have an fdc go ahead and bypass it. You don't need it and it's a common fail point.

To check the hydraulic head o rings you simply remove the shut off cover from the injector pump. Then turn on the master power switch. Look inside where the cover was (you may need a mirror) and look for dripping. If you see any fuel dripping in that cover then the fuel control rod o ring and the 2 o rings under the hydraulic head need replacing.

The booster pump is the hardest one to deal with. It's located on the injector pump right next to the steering box. Which makes it difficult to remove.

To test you simply remove the screws holding into the injector pump. Slide it out as far as you can and turn the master power on and see if fuel drips out.

Click to expand...

mhassett said:

Then only place that fuel is on one side of an o-ring and oil on the other is the hydraulic head.
Remove and by-pass the FDC.
5 minute job.
Had same problem.
MHassett

Click to expand...

Great idea....will start here.

mhassett said:

Then only place that fuel is on one side of an o-ring and oil on the other is the hydraulic head.
Remove and by-pass the FDC.
5 minute job.
Had same problem.
MHassett

Click to expand...

Not true. The booster pump seal also has fuel on one side and oil on the other.

The flame heater nozzle can also theoretically contaminate the engine oil but this is the least likely scenario.

If I find that the fuel supply pump is leaking, would it be possible to replace said pump without removing the IP? It doesn't look possible unless the steering shaft is removed.

Mach830 said:

If I find that the fuel supply pump is leaking, would it be possible to replace said pump without removing the IP? It doesn't look possible unless the steering shaft is removed.

Click to expand...

You basically have 3 choices on how to deal with removing the booster pump.

1. Remove the entire injector pump. Probably the easiest method if you don't have a way to lift a 1600 pound engine.

2. Remove front and side motor mount bolts and lift the engine a few inches and then pull it towards the passenger side of the truck.

3. Remove steering box. This would be the least fun of the 3 options.

Thanks, digger. It would seem that dropping the IP is the simplest option.

Mach830 said:

Thanks, digger. It would seem that dropping the IP is the simplest option.

Click to expand...

Pulling the IP is in no way simple or easy, it requires quite a bit of work! I'd start with the orings on the HH and shut off shaft,that usually fixes it.
If you end up doing the booster pump,i think jacking the engine up to gain access would be way easier than pulling the IP.
Just my opinion,good luck.

RAYZER said:

Pulling the IP is in no way simple or easy, it requires quite a bit of work! I'd start with the orings on the HH and shut off shaft,that usually fixes it.
If you end up doing the booster pump,i think jacking the engine up to gain access would be way easier than pulling the IP.
Just my opinion,good luck.

Click to expand...

I guess that's a matter of opinion. If I have someone to help me roll the engine over to line up the timing marks I can have an ip off in about 30 min. An hour if I'm by myself.

This does depend on how hard it is to get the injector lines out of the hh. Which you would need to do to change the hh o rings anyway.

If you loosen all the injector hold down bolts and just unseat the injectors ( no need to pull them out), you can roll the motor over by hand from the fan. I did it today adjusting my valves. Way easier than barring the engine over by the jackshaft, and as you know, I'm always by myself.