Combines 6600 Diesel in the Oil

I had this happen on a 4320 with a 404 turbo engine. We rebuilt the injection pump but it still leaked because the shaft was grooved and would not seal even with a new seal. The other possibility is that the mechanical transfer pump is leaking into the crankcase. Hope this helps!

Take a good look at the transfer pump, it and the injector pump are the only two posible ways for fuel to get in the crankcase,it being the easier and less expensive to change.