Good Morning all,
I've replaced the IP on my 1996 3500HD with the 6.5. Put in a reman pump from Pensacola Diesel. Truck started on first crank and runs great. No timing issues no hesitation no problems does everything it ever did.

The problem I have is that I'm getting oil leaking from the lower passenger stud area on the mating surface between the timing cover/block and the IP itself.

When I first noticed the leak, I pulled the pump back off and at that time noticed that that stud was loose. I thought great, tightened the stud and put it back together. No luck...still leaked. Then pulled it again, stud was tight so I thought maybe the surface is a little off so I used two gaskets. Still leaking.

Pulled it again and am now stumped.

One theory I have is that the flat surface that is at the bottom of the mounting flange on the truck might be interfering with the pump mating surface and causing just enough of a bind for oil to leak? You can see the surface I'm talking about in this picture.

If this is the case, maybe i could bevel the edge of the pump flange where it meets in this corner to give just a mm of relief and allow the surfaces to seal?

Any thoughts?

 

Are the studs into blind holes, or do they lead to where the oil is? If they can get wet, oil may be seeping past the threads. I'd pull the studs, clean them and the holes, then reinstall with some blue Loc-Tite.

 

Yeah, the studs go through. I thought I had the stud leak licked but maybe not. I will double triple check the stud.