John Deere 4020 Fuel in oil.

[977cat]

Hi all. I have a John Deere 4020 that is getting diesel in the oil. Dealer says it needs Injection Pump. I've never used a additive to lube the pump and wonder if the pump is worn because of this. Has 5500 hours on it and runs good except for an occasional rpm surge when I have my wood spliter hooked to it. If it sits all winter it will have about a gallon of of fuel added to the crankcase. Wonder if anybody else has had this problem Lloyd Powell Butte, Or.

 

[jd110]

The fuel transfer pump could be bad also. The diaphragm will sometimes leak. If it is the injection pump, you might just need new seals on the shaft. If the bushing in the housing is ok, then a couple of dollars worth of seals will fix the leak. The surging rpm would probably require q rebuild to repair.

 

[977cat]

Thanks for the reply jd110. The transfer pump was one of the first things I was going to check. I also own a 1960 Cat 977 track loader and had to replace the seals in the IP for the same problem. Lloyd

 

[RickB]

A bad transfer pump diaphragm could let fuel into the crankcase AND air into the fuel supply causing your surging. Replace the transfer pump, then if the surging continues, the injection pump governor retaining ring will need replacing.

 

[977cat]

Thanks for taking the time to reply Rick. I'm going to replace the transfer pump next weekend, it is the original. I'll post the results after I get it on. Thanks again,
Lloyd