jd4020 diesel in oil

[callmefence]

I went out this morning to get my 4020 ready.
Hasn't been run in probably 6 weeks.
Hook up battery charger, check coolant and oil , both good.
I start the tractor it starts and runs normal but almost instantly begins dumping fluid out of front engine area. I turn it off . Every thing is covered from fan slinging oil. I removed the fan belt and still can't tell for sure because of the oil coming off the crankshaft pulley. Finally by blocking off the crankshaft with a piece of cardboard. I'm able to narrow the leak down to the front seal area.
I notice the oil is looking and smelling more like diesel than oil. Check the oil and it's 2.5 inches overfull very thin. No leak while tractor is off. Running huge leak.
I only ran the tractor a few minutes total and I captured a half gallon of the oil/diesel. And that much more is easily spilled and on the tractor and me.

Any suggestions much appreciated

 

[callmefence]

Just occurred to me. The lift pump?

 

[Atimm693]

Yep, if the diaphragm in the lift pump gets a hole in it, it'll dump fuel right into the crankcase.

An injector that has failed and stuck open can do it too, although at a much slower rate, and there's usually a skip and smoke along with it.

Neither would cause an oil leak, and neither would be able to dump quarts of diesel in a matter of minutes.

I'd think a leak that big is probably going to be the shaft seal on the injection pump.

 

[Kingfisher]

Sounds like you have 2 problems. Oil leak and diesel leak.

 

[wbvs58]

Yep the lift pump. My old Chamberlain, (Perkins 6 cyl) was pushing oil out of everywhere running down over the exhaust manifold. The level on dipstick was very high. It wasn't as sudden as yours and I used it a bit knowing the problem before I got around to replacing the lift pump. It fixed the problem and no more oil forced out of all the old seals just took a while for the oil to burn off the exhaust. I must say that it hasn't run better for a long time, she is just an old tractor I leave at my other block but I used her hard for 2 days the other week slashing long lovegrass and she burnt very cleanly and the oil since I changed it has taken a long time to get a bit of the black colour to it, gave her a good clean out.

Ken

 

[Nesikep]

What type of pump it is? A CAV pump like this?


There's a seal on the front of those that can leak, and it'll go right into the engine oil.. Lift pump CAN do the same thing, so I'd start with that. Good news is it's not terribly hard to rebuild these pumps, and the complete seal kit is only $25... Just last week I did 2 of them...
Here's how mine looked before I washed it up

 

[callmefence]

What type of pump it is? A CAV pump like this?


There's a seal on the front of those that can leak, and it'll go right into the engine oil.. Lift pump CAN do the same thing, so I'd start with that. Good news is it's not terribly hard to rebuild these pumps, and the complete seal kit is only $25... Just last week I did 2 of them...
Here's how mine looked before I washed it up

Thanks everyone

Nesi
Yes I believe that's the same injection pump. Mine has a fairly new rebuild on it.

I think I was wrong about how fast the fuel got in the engine. Yesterday I pulled off the lift pump and drained the crankcase. I got 6 gallons out of the crankcase :shock:
I mocked up the pump on vise and pumped fluid through it. No visable leak.
The intake side would not hold vacuum.
I put the pump back on and filled crankcase with oil. Started and ran tractor no leaks. I let it run about 30 minutes. No increase in oil level.
I believe maybe fuel seeped all winter through the pump diaphragm. When I did the routine quick oil check the diesel was on top of the oil and I simply didn't see it. Once I started the tractor the fluids mixed . and became visable on dipstick.
Does that sound possible??

I've ordered a new lift pump.

 

[callmefence]

Taking another look I think my injection pump
Is different than the one you show

 

[Nesikep]

That is a different pump, I think that's a Roosa Master, our JD350B crawler loader has that.. theory of operation behind them is exactly the same, just a little different design.. and subject to the same potential problem with shaft seals.