Diesel fuel getting into crankcase of JD

Paulinkansas · Mar 17, 2009

Deere 830, it's a 3 cylinder diesel and about 35 years old. I can change the crankcase oil and fill it with new oil to be in the middle of the "add" add "full" mark on the dipstick. After running it for a few hours, the level on the dipstick is above the full mark. I have changed the gaskets in the fuel lift pump (it's a cam operated pump by the fuel sediment bowl).

The oil on the dipstick is very watery and it smells like diesel. I turn off the petcock under the fuel tank when the tractor is not in operation. The tractor needs an oil change every 3~5 hours because the level in the crankcase gets so high.

How is the diesel getting into the crank? Could it be bad rings? The tractor runs smoothly otherwise.

Mike (WA) · Mar 17, 2009

Most common source is a ruptured diaphragm in the lift pump- you mentioned you changed the gaskets- did you rebuild the pump and put in a new diaphragm? Probably too much diesel getting into the crankcase to be blowby- rings would have to be so worn that compression would be affected and tractor would start hard and run poorly. About the only other source is leakage through the injector pump, and I don't know enough about that to comment.

Bill Shafer · Mar 17, 2009

Not sure what injection pump that engine has. But it may have bad seals in the pump.Some have shaft seals that will dump fuel into the oil id bad.

4010 puller · Mar 17, 2009

Shut er down immediately. This is how I lost the engine in my 4010. You could replace the lift pump on side of engine first, if it still does ti take the injection pump off to have seals replaced. Cheaper to do it now than after it overfills and engine wipes a bearing.

Stephen in SoKY · Mar 17, 2009

Just went through this on my 1980 model 2240. Replaced the supply pump, still dumping diesel into crankcase. Had the injector pump rebuilt, tech said the input shaft seal was the problem. Said it was hard as stone & slightly scored. So far it"s performing perfect & NOT dumping diesel.

Brian Jasper co. Ia · Mar 17, 2009

I'm pretty sure that tractor is a Manheim Germany built machine. Probably has a CAV or some sort of German Bosch pump on it. If you're lucky and it's like a Roosa Master pump, you can slide the input shaft out easily, replace the seals and put it back. I just did that on a D17 that has a Roosa pump on it. The seals were about $3.

Diesel fuel getting into crankcase of JD

Paulinkansas

Member

Mike (WA)

Well-known Member

Bill Shafer

Member

4010 puller

Well-known Member

Stephen in SoKY

Member

Brian Jasper co. Ia

Well-known Member

Similar threads