JD 4020

[Bellschool]

My JD 4020 started blowing oil and fuel out the crankcase vent tube. I shut it off and checked the oil level and it showed nothing on the stick. It was full before I started it.
Does anyone know the cause and what the repair might entail?

 

[Texasmark]

Wipe the dipstick, reinsert it and bring it out for inspection. If your oil was in like new clean condition and you have a stainless steel stick, you may not be able to see the level. Take a sample again and lay it on a paper towel and then lift it off. The actual level is easier to see that way.

How about more information as to what was going on before and after the blowout occurred. How you know fuel was also being blown out? When was the last time you ran the tractor? Any unusual happenings then?

 

[NY 986]

Fuel would be introduced via the transfer pump or injection pump due to a seal failure most likely. Is the transfer pump the old style with the primer lever? If so work the lever for a few minutes and see if the level on the dipstick rises. Newer style you may have to pull then while over a pail work the lever that normally runs off of the camshaft. If no leaks with the transfer pump then the injection pump has a leak. A stuck valve would create blowby into the crankcase which would in turn push oil out through the breather. Doubtful that you would have both problems at once so be sure to eliminate the possibility of fuel in the crankcase.

 

[Bellschool]

Thanks for your suggestions. This morning I checked the dipstick and it was above the full mark. I decided to drain the oil and it filled a five gallon bucket. I thought I was going to need another, but luckily I didn’t. A mixture of oil and diesel fuel.

 

[Fixingfarmer]

so half of the oil or so is fuel. Probably why more is making it out the breather tube if there’s so much fuel it will be lighter. It’s highly likely it’s a transfer pump leaking into the crankcase that’s where I’d start it’s cheap

 

[Princeton Bill]

When you fix the pump and put new oil back in the crankcase change the oil filters also. There will be residual diesel in the filters.

 

[Bellschool]

I changed the filter and oil. Got the new pump installed. Primed the fuel line. Tractor started and ran fine for about 15 minutes and then died slowly. I’ve bled the fuel filters and it would run for a bit and then died again.
Should I bleed the main fuel line at the injectors?
Can’t thank you people enough for your help.

 

[Fixingfarmer]

so you are getting fuel at the filter then? If you crack an injector line do you have fuel?

Headed down the main injection pump path possibly…doublechecking the rest of the lines

 

[used red MN]

I changed the filter and oil. Got the new pump installed. Primed the fuel line. Tractor started and ran fine for about 15 minutes and then died slowly. I’ve bled the fuel filters and it would run for a bit and then died again.
Should I bleed the main fuel line at the injectors?
Can’t thank you people enough for your help.

Hello Bellschool, welcome to YT! We need to know a bit more about the tractor. Have you been using it as a working tractor before this happened? It sounds like the governor weight flex ring is coming apart in the injection pump. When this happens small chunks of plastic plug the check valve in the return line coming out of the pump. When this happens pressure builds up in the pump housing and the high pressure pumping elements in the pump can’t return to draw in fuel for the next stroke so the engine stalls. A way to test for this is to slightly loosen the two screws on the small rectangular timing window to let some fuel leak out when the engine starts to stall. If the leak off allows the engine to continue to run this verifies your problem. If this is the case the bottom line is the pump needs to come off to be rebuilt.
Edit to add: I asked about it being a working tractor because it seems odd that you would have a transfer pump problem that filled the crankcase with fuel and then turn around and have an injection pump problem as well. Odd coincidences can happen. If this is a tractor you are just getting familiar with and are running it more than it has been for a time then coming across multiple problems is not so unheard of. Secondly, leaking drive shaft seals on an injection pump can also let fuel into the crankcase so you may actually have “a two for the money” problem with the IJP.

 

[Tx Jim]

Ditto on loosening the 2 screws securing timing window on inj pump. With fuel leaking start engine & if engine continues operating check valve in fitting that fuel return line attaches to on IP is clogged. If check valve is clogged IP needs to be rebuilt. If that's your situation then you need to contact YT member Dieseltech whom rebuilds inj pumps.

 

[Bellschool]

We use the tractor very little. Primarily it pulls grain wagons out of the shed and is used to back them into the shed after harvest. Its narrow front end is great for backing wagons into tight spaces. It probably doesn’t get five hours of run time.
Today’s temperature has kept me inside, so no attempts at solving the fuel issue.