Oil & Fuel JD 755 fuel and oil mixing

[Wolfman37]

Son was driving tractor. Somehow, the fuel line became disconnected???

He re-connected it. Fuel ends up in the oil.

Drained oil/fuel mixture. New filter, new oil.

Tried to bleed the system, no bubbles. Loosened injectors - no bubbles. No fuel into the sediment bowl.

Fuel still going into oil.

What is wrong, and how do I fix it?

Thanks for any suggestions.

 

[beenthere]

Those the most details you can offer? What fuel line? How does it get reconnected for the fuel to end up in the oil? And which oil....the hyd. oil or the engine oil?
Is the line reconnected to the right place now?
Is the son a mechanic? Not that it really makes any difference.
Need more info.

 

[Dennisfly]

Does this tractor have a low pressure mechanical fuel pump that primes the high pressure injector pump? If so, it could be a hole in the diaphram of that pump. The fuel could leak through the diaphram into the oil where the mechanical drive arm of the pump enters the block. If the diaphram is shot, it would also explain why the sediment bowl isn't filling. If the sediment bowl doesn't fill, the tractor is not going to start.

Regarding your son reconnecting the fuel line, I don't know.

I have an 855 and I believe some models use a mechanical transfer pump and some use an electrical one.

Go to the John Deere parts web-site and look at the exploded view diagram