There 2 types of vacuum pumps used on MB Diesel engines. One has a sort of flat end and the other is round, sort of like a small electric motor.

What are the differences in these 2 pumps? Which is the better one? Can one be replaced with the other? Which one or is it both that can self destruct and it's parts get into the engine and cause damage to the engine?

P E H

There are piston and diaphram vacuum pumps, my '76 has the diaphram type but the parts sites list both for that year. I am not sure if they are interchangable. My engine drives a wheel with hills & valleys. The pump has a roller that rides it and pushes the diaphram in and out.

Steve,

My wagon has the piston type pump. I just rebuilt it recently and it sounds very similar to your's in that mine also has a roller that "rides" the hills and valleys. I'd be interested to see the two side-by-side.

__________________
Dave
1995 C280
1999 Triumph Daytona 955I - my speed fix.
1982 300TD - Gone, but not forgotten.

Sounds like the piston type is the newer version. I suspect it is the better design. I have had experience with airless sprayers and the piston types are the only way to go. I rebuilt my pump, the old diaphram was not damaged but worn. Sounds like the pumps are interchangeable but I would verify it with some one more knowledgable. I pull about 15in of vac which is spec for my model. I am planning a trip to the salvage in a few weeks. I'll try to pull some pumps for comparison.