Gaining oil

[Irv1Dehut]

B20 Kubota TLB. It was gaining probably an inch on the dipstick in an hour. I replaced the fuel pump with an oem from Coleman's Kubota. Still gaining the same. Next I removed the injection pump and took it apart and didn't see anything wrong with it, just cleaned and reassembled it. Put it back on and used it for two or three hours and it didn't gain at all. A couple days later I used it and it gained about half inch in probably three hours. It's a cast iron Diesel Kiki pump. Any suggestions on what to do next would be greatly appreciated.

 

[ptsg]

Since you rule out all the possible sources from being fuel, I would say the issue is in the hydraulic pumps.

Usually, it's the shaft seal of the hydraulic pump(s) that fails and lets fluid get inside the engine, since those pumps are mounted in the timing gear cover.

 

[Roadworthy]

I agree with ptsg. If the seal is leaking the hydraulic fluid goes straight to the oil pan. I went through two hydraulic pumps on my Mitsubishi tractor for the same issue.

 

[OldTrix]

That is my guess as well, as that just happened to me. Was digging away with the backhoe and turn around to a nasty cloud of exhaust smoke. By the time I could get in the cab, it was on runaway from an overfilled crankcase.

 

[Irv1Dehut]

Thanks for the replies, I appreciate it.
The hydraulic pump is a good suggestion I never thought of but I don't think that's the problem because I took the injection pump apart and after I put it back together it didn't gain any oil for several hours or more (probably more like six or eight hours. I should have also said that I put fluorescent
die in the fuel tank and now it's in the engine oil. Before I took the pump apart it would gain a lot on the dip stick in a short amount of time(Like probably an hour). Now that it's gaining again it's at a lot slower rate than before. Today I took the pump apart again and polished the fuel needle valves and seats and put new springs on top of the valves. It starts and runs good. Tomorrow I'll give it a work out and report back. Also when I do find out what the problem is I'll let every body know.

 

[RayIN]

I had leaking injectors fill the crankcase once. Rather than try to find the leaking ones, I replaced all of them. No more making oil

 

[redman135]

If diesel is getting into the crankcase, check the seal on the injector pump driveshaft to timing chain as they can fail and fill the crankcase with diesel.

 

[hayden]

Draw an oil sample and get it analyzed. That will tell you what's in the oil so you don't have to guess.