I just got done killing the dowel pin and have a very serious oil leak on the from of the engine. It appears to be the lower vaccuum canister on the vaccuum pump as it's clean. The rest of the area is covered with dirt mixed with oil. Any ideas on what's leaking? I'm planning on pulling it out tomorrow.

 

I recall the early vacuum pumps being different from the later ones in that they used two diaphragms instead of just a vane pump. I've repaired those early ones with leaks, and I think it is usually just a small o-ring that seals the diaphragm housing to the main pump housing. You need to remove the pump, then some small bolts that hold each diaphragm to the pump. You will see the o-ring where the diaphragm's pushrod enters the pump housing.

It's been a long time, but I think that's the jist of it.

 

Thanks, I was kind of thinking along those lines. Don't see anyplace other than that it could be. Given the only "clean" part is the bottom canister. Everything else is kind of crusty. I drive it, I don't clean it.

 

Here you go, I did a write up on how to repair the vacuum pump.

There should be an o-ring and a possible gasket on the lower plate.
Jim

https://www.dieseltruckresource.com/...d.php?t=165546

 

Thanks Jim. I had read that and got my info from it. Great article. Didn't see anything about an o-ring on the canister itself, but kind of figured there had to be.
Rick