hello guy's, i've got a 90 cummins that is getting fuel in the crankcase. replaced lift pump. no good. I just had a friend that knows about these things check it out and he says injectors are fine .He believes that the front drive shaft seal of the pump is bad. my question is can you just replace this seal? if so what is involved? i really need to go this route if possible any help would be greatly appreciated. thanks C.L.

 

You have to remove the pump from the engine, naturally. There is even directions in the 1993 FSm on how to change the front pump seal. It woul dbe a good time to change all the other seals as well. Gasket/ seal kit is $20 or so. If you dont feel comfortable doing it yourself, find a good shop that can do it. I know of one in Jackson MO that can do it fairly cheap if you want just seals.

Daniel

 

The parts are readily available, and here is a diagram and part numbers from one of the members here:https://www.dieseltruckresource.com/...ont+shaft+seal

 

I don't know where you are exactly in North Central Texas, but if you're in the DFW area, Southwest Metro Fuel Systems in Ft Worth is the place to go. An old guy named Stan runs the place and he's forgotten more about these pumps than most guys ever know. He's done mine, and lots of other people's pumps that I know.