JD 2440 Diesel leaking into the engine oil (I prefer to keep them separate)

[xzcVAbc5]

I have a JD 2440 with a problem. Diesel is leaking into the engine oil somehow. So far I have replaced the lift pump and that did not fix the problem. What other things should I be looking for to fix this problem?

Any help is appreciated and thanks in advance.

 

[Zebrafive]

Front seal on the injector pump.