Any sources for a vacuum pump piston? - PeachParts Mercedes-Benz Forum

Nate Stanley · #1 04-18-2003, 02:41 AM

This is the second time in 35,000 miles that the piston has broken in the vacuum pump.

Car is the '79 300D with a late-style pump.

Has anyone else had this type of failure? The boss where the bolt passes thru fractured and broke completely away from the rest of the piston.

I have the valve kit w/ O-rings, just need the piston for now.

On the other hand, I also have access to a CNC milling machine, and given enough time and demand, I would be able to produce these fom 6061 T6 aluminum instead of the weaker cast materials currently used.

If anyone is interested, let's set up a poll and find out what a good production run this would be-- and perhaps I will be able to supply a competetive price.

Any thoughts?

Stevo · #2 04-18-2003, 01:02 PM

Nate

Just wondering..did the late type come with the car as I thought they started in '80" I would think you might have a problem with the mechanism running the pump as 2 pumps failing in 37K is a tad much. Not allot of help, sorry.... but I am curious about the late model pump on a "79" as I have cars with both types and have never had to get into them. Good Luck

Nate Stanley · #3 04-18-2003, 01:15 PM

Stevo,

All I know for sure with respect to the 2 types of pumps is that the one on my car has one hose protruding from the top, and the earlier version, according to the previous owner, had two hoses, one going to the brake booster and the other to a hole in the top of the air filter housing.

I am also leery of the pump because of the second failure, OTOH the piston is a die-casting (not much inherent strength) that has to ba slammed back and forth 2x per injector pump revolution.

Maybe after 20 years of this, more of them will start giving out--
Who knows?

That's why I'd like others to weigh in on this issue--

Thanks, Nate