Leak from AAZ injection pump

[VR6zamboni]

Hello,

Can someone please help me out with this leak coming from the bolt on my injection pump.

LeakyInjectionPump by RockOcean.com, on Flickr

What does this bolt adjust?

What do I need to do to fix the leak?

And how do I make sure that I get it adjusted back to where it was?

Thanks again,

Ryan 82' Westy AAZ intercooled

[?Waldo?]

If you are talking about the part with the yellow paint on it that will take an odd socket to remove (circle with two flats cut in it), then it is the internal pressure regulator which controls the dynamic timing advance. It has an o-ring (actually two, but it looks like the outer one leaking). Get a six point 10mm socket and round out four of the six sides appropriately. Twist it out, swap the o-ring, twist it back in. The o-ring is available at any Bosch dealer. It is installed flush, so there is no adjustment necessary to swap the o-ring(s).

[VR6zamboni]

Yes that is it - at first I thought it was coming from the fuel supply line. But after cleaning it all up, and starting the engine again it is coming from the funky nut with the yellow on it.

Thanks again!

[VR6zamboni]

I ended up using a green o-ring that looked the exact same size as the one that was in there.

It works, no leak!

But do I need to be worried about it not being made for a diesel application - and possibly breaking down sooner then later?

I believe it was a factory o-ring for an A/C system.

[Derek]

Resurrecting this old thread because I've discovered a similar leak on my AAZ pump on the part above the return. I think it's the same location as the original post, but the head appears different. It's a very slow seep while running that will slightly mist under load. Is this the same internal pressure regulator as the OP or that can be remedied with some O rings?

[?Waldo?]

Nope, that is a failure of a different seal that is quite hard to get to.

[VR6zamboni]

Funny to see this 10 years later. I now have what looks to be oil occasionally spraying out of the square fitting pictured above. Is that even possible?

[?Waldo?]

It is possible for oil to leak out there. That orifice leads to below the diaphragm of the boost pin. Above the diaphragm is exposed to boost air and that boost air will have some oil in it from the crank vent. If the oil is reaching the lower part and there is enough that it is leaking out, then likely the boost diaphragm is leaking and should be addressed.