JD 855 fuel prime and leak issue

[bayfarm]

Need some help with fuel issue on JD 855. Fuel system kept losing prime. Discovered fuel in crankcase oil. After tractor sat a few hours all fuel siphoned into crankcase. (Has a mechanical fuel pump on this model) I had suggestion that bad fuel pump was allowing fuel to pass into crankcase??? Other than part swapping, any other suggestions for tracking down reason? Many thanks in advance.

 

[loggin]

Need some help with fuel issue on JD 855. Fuel system kept losing prime. Discovered fuel in crankcase oil. After tractor sat a few hours all fuel siphoned into crankcase. (Has a mechanical fuel pump on this model) I had suggestion that bad fuel pump was allowing fuel to pass into crankcase??? Other than part swapping, any other suggestions for tracking down reason? Many thanks in advance.

Usually it is the mechanical diaphragm fuel lift pump that is allowing fuel into the crank case. You can either replace the pump or cap that spot off and install an electric fuel lift pump. With the electric conversion you would never get fuel in the crank case from the lift pump again.

Hope this helps!!

 

[bayfarm]

Thanks, that was the direction I was working towards. I removed pump. I opened fuel pump and added a small puddle of water. When activating the pump by hand, water did flow out of the plunger end. The plunger would be inside the injector pump and allow fuel to enter oil. This machine has MANY hours on it so will probably go with new pump and hope it will fix the problem.

 

[loggin]

Thanks, that was the direction I was working towards. I removed pump. I opened fuel pump and added a small puddle of water. When activating the pump by hand, water did flow out of the plunger end. The plunger would be inside the injector pump and allow fuel to enter oil. This machine has MANY hours on it so will probably go with new pump and hope it will fix the problem.

Replacing the pump will be the easiest way to go. If you are still getting fuel into the crank case, after the lift pump replacement, then there is likely a problem with the injection pump. Here's hoping that's not the case!!