Hello,

On my 83 SD the vaccuum system is malfunctioning. On occasion, (usu startup), the power brakes, transmission act as if they aren't receiving vaccum (hard shift, hard brake pedal). However, the problem has resolved always in 10 minutes of driving. Sometimes days go by without any problems.

Essentially intermittently no vaccum. Sounds like a bad vaccuum pump?

Thanks
mbz owner
84 SD 240K
83 SD 130K

Yes sounds like you have a bad vacuum pump
remove the vacuum line at top of pump check in side should have a check valve if not
check with online partsshop should have repair kit for it or have someone repair for you...also check your brake booster for leaks
and other vacuum system.
hope this help

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MB STARS Master Guild Technician,12 years MB tech
5 years independent shop owner

Check the check valve that is in the top of the pump located directly under the brake booster line. Some times it will break out and float around. If so you will need a magnet to fish it out.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Can I just buy the valves? if so, what are the part numbers?

David

Ok

so it sounds like the valve is the first thing to check. So you unscrew the line to see if it is there, if not check to see if it fell inside? It sounded like it can be "missing" on some models?

so if has fallen or floated do I just set it back and thats it or do I still need a new pump?

Also, the repair kits have this check valve in them?

Thanks for the quick responses. I need to have the car up and running fast. To replace pump, do you need to remove radiator and belts, or can you slide it out without having to do that (83 SD USA)

I think the kit contains more than one valve and other parts. There are moving parts inside the pump subject to wear and tear, such as bearing. There is no need to remove the radiator. You may have to move the power steering pump aside. You need an allen wrench with the right length (about 6" ?) to remove the mounting bolts.

David