Oil & Fuel Diesel get into oil

[hentie]

I ve got a Newholland 8066 tractor.All of a sudden the oil level started to rise. The oil also gets thinner.
I ve replaced the small liftpump, but it didnt help. Then I replaced the shaft seal on the CAV injector pump.When I installed the seal on the pump I noticed that the seal is not exactely the right size(a bit loose on the shaft). I started the tractor very easy.
But it picks up revs by itself when idling, and then it will decrease the revs by itself. Except for this the engine runs smooth.
Is it possible that when a lot of diesel is bypassed through the seal again that it wil cause this symptom. I wil go and get another seal. Or can it be something else. I ve only replaced the seal.
Thanks

 

[Topher265]

If the oil level is rising and getting thinner, either fuel or coolant is contaminating it. You can usually smell the oil on the dipstick to determine which is getting into the crankcase.

Based on your other issue, I would suspect fuel also. You may be using the correct seal, but the shaft may have a worn area that is letting the fuel bypass. You may need to sleeve the shaft (if possible) so that the seal fits properly.

 

[Recoveryhill]

Many machine shops can spray weld a metal deposit on worn shafts and turn them back to the specified diameter. The rule for using such a repaired shaft is that there can be no point contact or the deposit will crack. A bearing inner race is fine as is a seal. Inner and outer diameters being correct within a few thousandths of an inch are absolutely critical for bearings and seals to function correctly. Any slop and you're doomed.

 

[hentie]

Thanks for all the advice.
I have replaced the shaft seal with a new one from the dealer, drained the oil and let it run for
about 2 hours. The idling was immediately fine after replacing the seal and there is no more rising in the oil level.
So it seems that the problem is something of the past