Case 680E

[Eugen]

@Eugen Try depressing the the plunger all the way and blow air through . Like an engine it may leak more at TDC than at BDC .
There seam to be a lot of scaring on the piston .

Dave

It's air tight in all positions.


Now I'm thinking either the injection pump has an internal failure and it dumps fuel in the camshaft area, or the liquid in the oil pan is not diesel.

[Eugen]

Found this nice image of an injection pump of the type I got. For fuel to make it from where the arrow points to the camshaft, it would have to be able to go down between the plunger and sleeve (piston and cylinder).

The plunger and sleeve are supposed to be mated with very tight tolerance, so for fuel to go down so fast there would have to be some catastrophic wear. Somehow I find this also very unlikely.

[Timj]

Ok, wow, I guess about as simple as it gets. Can't believe it doesn't have any seals or wipers. Fuel seems to find it's way past gaskets, seals, and threads with ease. Surprised it can maintain prime.
Well, what little would leak past wouldn't fill the crankcase that fast.

[Eugen]

Yeah, I know Tim, I guess if you machine and mate your parts well you can have a pump like this working for many years with insignificant leak by. I found out that this very pump model has been used as feed/lift pump for many many engines, Mercedes included. Clearly this is from an era when Bosch made quality stuff. At least I'm getting an edekation here

[Eugen]

Finally found a better image of the camshaft seal and general are. Makes it even more unbelievable that fuel somehow makes it into the oil sump of the injection pump, and then past the seal and/or end gasket.

I'm veeeeeery puzzled right now.

[Eugen]

Ha, don't know why I wasn't able to find the service manual for the injection pump before. This one has some interesting information, as you may well think.

There's a designed oil drain on the side of camshaft end. So, oil eventually is supposed to come out of there and into the timing gear cover, and then crankcase.

But then a few pages later there's a more detailed feed pump parts diagram. Looky looky part #12 -- an oring?! But really, how would that make any difference at all? Got excited for a microsecond there.

[DavidBarkey]

Found this nice image of an injection pump of the type I got. For fuel to make it from where the arrow points to the camshaft, it would have to be able to go down between the plunger and sleeve (piston and cylinder).



bosch_inline_pump_view1.jpg



The plunger and sleeve are supposed to be mated with very tight tolerance, so for fuel to go down so fast there would have to be some catastrophic wear. Somehow I find this also very unlikely.



CAV13.jpg

If it was leaking past anyone of the plungers it would not build pressure and that cylinder would not fire and since you said it ran fine I would eliminate that .
What just accrued to me is if one of the injector pumps had backed out a little when someone in the past doing a repair that required removing the lines and did not properly re-torque them . Fuel would be able to leak from from the fuel passage to the shaft area . From what I can see each pump is seal at the bottom by clamping force. This type of leak could still alow the injector to function . Other possibility is that at some point the was water in the system that froze and there is a crack internal , but i would expect that if that was the case there would have been other damage .
I think before going any further , A- drain some oil off and see if it has water in it or is just thin and smells of diesel , B- If it is water go down that path , if it is thinned out by diesel go to step C.
C- remove the lines from injector pump and make sure all nuts are free . release the clamps and crack loose each injector slightly to make sure move freely enough and re-torque down to spec. re-assemble, chain oil again ( don't worry about the filter just drain it and put back on ) and call me to come over and give you a hand bleeding the injectors .

Dave

[Eugen]

If it was leaking past anyone of the plungers it would not build pressure and that cylinder would not fire and since you said it ran fine I would eliminate that .

I don't about running fine though. Listen to the same model tractor that I found on youtube, sounds to me more smooth:

https://www.youtube.com/watch?v=0YI9rtOIF5g&t=70s



Whereas mine sounds like tar-tar-tar-tar

Maybe that's a sign that fuel delivery or pressure wasn't right anyway.




I don't have experience with diesel engines so I'm not sure if it sounds like it's got a problem or not.

What just accrued to me is if one of the injector pumps had backed out a little when someone in the past doing a repair that required removing the lines and did not properly re-torque them . Fuel would be able to leak from from the fuel passage to the shaft area . From what I can see each pump is seal at the bottom by clamping force. This type of leak could still alow the injector to function .

I can try to re-torque them, yes.

Other possibility is that at some point the was water in the system that froze and there is a crack internal , but i would expect that if that was the case there would have been other damage .
I think before going any further , A- drain some oil off and see if it has water in it or is just thin and smells of diesel , B- If it is water go down that path , if it is thinned out by diesel go to step C.

If there was water or coolant in the oil, shouldn't the oil have been bubbly/cloudy after it ran? A buddy of mine had a boat whose engine wasn't properly winterized so the manifold cracked and there was water in the oil. We didn't know right away, so we tried to run it, started for a few seconds and then died. But the oil was cloudy/gray.

C- remove the lines from injector pump and make sure all nuts are free . release the clamps and crack loose each injector slightly to make sure move freely enough and re-torque down to spec. re-assemble, chain oil again ( don't worry about the filter just drain it and put back on ) and call me to come over and give you a hand bleeding the injectors .
Dave

Will try the re-torque. But can't run it at all, as i'm missing those parts for the fuel return line and waiting for them, plus the feed pump. I'm going to take the injectors to a shop in Toronto to have them looked at and if needed fix/clean them.

[Eugen]

Some pictures of a piston with broken rings that came out of my Ferguson tractor. That cylinder had 35 psi compression. Other cylinders had 60,85 and 100 psi. Tractor still was working cutting grass and sawing wood. Had a little trouble plowing at our Plow match thou.

Noel

That's nasty! I'm suspecting that one of the cylinders in this tractor doesn't work. But to check the compression on this engine I need a special adaptor that goes into the injector hole and it's $$.

[Eugen]

The amount of fuel pumped is very small, when you're bleeding them it's just a spit when that cylinder is fed. It would take considerable time to pump a quart of fuel through an injector and get to the crankcase, even if that cylinder was not firing. Say he was working the tractor, burning 2 gallons per hour, that would be 2 quarts per hour through that injector.
When my injector pump failed on my Ford 172ci on a drill rig, (twice)oil level was normal at startup, some time during the day oil and fuel was pouring out of the valve cover. The motor continued to run swimming in fuel. I kept smelling raw fuel went up front to find it running out.
We didn't mess around with it to see what failed in the injector pump, took it to a shop, you know the rest of the story.

I missed this message somehow.

I called a shop in Toronto and the guy said it's possible that something inside the pump went bad and lots of fuel makes it into the cam area and then into the engine. He said it would be most likely a $1000-$2000 repair. At some point I'll just swallow the bitter pill and do it, hopefully then get lots of use out of the tractor.