Injection pump leaking from "timing port"?

My injection pump is leaking from what used to be the timing measurement port plug on older diesels. No idea what is under there on an ALH pump. I can't tell if its just the large plug, the small plug, or both. Can I remove these and change the orings without pump parts flying out? Its leaking pretty badly.

I tried searching but came up empty.

Center plug is simply a copper gasket but it sees injection pressure. I'd just try tightening it. Might get lucky.

Big plug has a metal-metal knife edge internal seal that sees injection pressure and an o-ring that only sees case pressure. The plug is supposed to be a one use only but I and others have reused it. I assume because if the knife edge seal leaks you loose some fuel to the injectors and you might not know it.

No parts will fall out if you remove either plug.

Thats good news! sounds like an easy repair for my wifes beetle. Which is good because the leaking fuel has nearly destroyed the lower radiator hose, which I need to replace as well...

There is no copper gasket on the "timing port" plug on the IP on an ALH engines (there was on older pumps). The center plug on these pumps use a tapered metal-to-metal system. The large plug that the center plug goes into does use an o-ring to seal the low pressure are of the hydraulic head (it uses a knife-edge design to seal the high pressure area).

Mine was leaking a while back in the same place and we replaced just the o-ring, and the leak went away. Granted the socket needed to remove the plug is either home made or purchased; do not touch the "screw" in the middle of the plug they are preset and meant to not be adjusted by the owners I was told.

You was told wrong.

The center plug is simply a plug. Used to be a port for installing a dial gauge to time the mechanical pumps.

dieseldrive said:

There is no copper gasket on the "timing port" plug on the IP on an ALH engines (there was on older pumps).

Click to expand...

Learn something new every day. I've never had an ALH pump apart so I never noticed it had a tapered plug instead of the copper gasket on the old timing port.

Thanks guys, some big vice grips and a new oring later, no more leak!