PeachParts Mercedes-Benz Forum - View Single Post - What in particular causes vacuum pump failure?

whunter · #11 11-04-2007, 12:56 PM

In order, the most common issues:

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#1. System vacuum leaks allowing dust and trash to enter the vacuum pump check valves.

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#2. Pump piston seal fails = allows engine oil to enter piston cylinder = oil coating check valves, system vacuum leaks allow dust and trash to build up on the oil coated check valves, eventually holding the valves open.

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#3. Incorrect rebuild, very common.

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#4. System vacuum leaks allowing ABRASIVE dust and trash to enter the vacuum pump cylinder, scoring cylinder walls into junk = impossible to repair as a DIY = send in for rebuild or scrap it.

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#5. Bearing or piston arm failure.

Have a great day.