1755 Injection Pump

[AndrewF]

I have an oil leak coming from in between the Injection pump and the front cover. I have replaced the o ring and even siliconed the surfaces. Leak appears to be coming from aroun one of the studs. How are these studs fastened to the front cover? Appreciate the help in advance.

Andrew

 

[Larry from MD]

The studs are just screwed in usually they are slightly oversize on that side so they stay.

 

[e]

The studs you see are a version of a PEM stud which basically pressed into a hole and "clenches" into the metal. These are typically used in sheetmetal (such as the front timing plate on your engine) since a threaded hole won't provide the typical 1.5x thread diameter of thread engagement and there would hence be a risk of the threads pulling out.

A clenched joint will typically be liquid tight, but if it even loosens a little, liquid can seep through. So, it's possible either the PEMs have come loose, or someone has replaced them with regular studs or bolts. If the original PEMs are still in existence, then it could be possible to remove the timing gear and dab some RTV over the head of the PEM to keep liquid from passing through.

 

[Anonymous-0]

Most I had apart were welded in the steel plate.

 

[AndrewF]

These ones ended up being welded. Oil was seeping thru the weld. Thanks guys