PeachParts Mercedes-Benz Forum - View Single Post - VACUUM PUMP FAILURE! Are you neglecting yours??

kerry · #8 06-18-2012, 06:23 PM

Quote:

Originally Posted by vstech

THANKS Beagle!!!

Thus the vac pump should operate for less than 5% of the time that the engine is running, 15 sec at idle to 25” at start up (i.e. FSM spec.) and less than 10 sec to top up after braking IF you have no leaks in the vacuum circuit and the plate valves are sealing perfectly! Any leaks in the system will cause the pump to run continuously and it is not designed to do so. It’s no surprise then that those pumps are going to wear out, fail prematurely, and cause excessive wear to the thrust face of the fuel pump timer bronze bushing. If you have any leaks in your lock system isolate it until fixed as this will cause the pump to work continuously and also reduce braking efficiency.

this is extremely important, and most often neglected information I was unaware of!

ALL MY CARS will now be subjected to pristine vacuum service!!!

This is a good argument in favor of a vacuum gauge which could serve as an indicator of how much the pump is working.