1987 300D Vacuum pump replacement, oil leak - PeachParts Mercedes-Benz Forum

#1 10-28-2002, 11:45 AM

I have oil pouring out from base of front housing mounted, engine driven vacuum pump.
Finally found it after pressure washing engine. (Thought it was crank oil seal.)
1. I have maintenance CD but cannot find mention of vacuum pump removal ??? (I tried looking under brakes and fuel system as well as engine)
2. Can it be replaced without removing serpentine belt. Seems one bolt is behind belt tensioner.
3. Can pump be rebuilt without purchasing new one

Any suggestions very much appreciated.

joe p · #2 10-28-2002, 01:06 PM

I'd replace that arm type pump, the roller bearings will fail as it ages. 200k or so seems to be the life of them. Remove the belt, p/s pulley and tensioner idler and just unbolt the pump. Turn the engine until the new pump sits flat on the timing cover and bolt it on.

Joe

md21722 · #3 10-28-2002, 01:10 PM

If the the tensioner is original, it will probably need to be replaced. You may wish to change the shock. I did not need to remove the PS pully when I did mine.

Brian

#4 10-30-2002, 03:51 PM

Just to complete the story. Ordered new vacuum pump from Fastlane, including gasket $260.00 (From MB quote $595.00 with gasket and Performance Products $323.00 with gasket.) Intestingly the new pump comes with its own gasket. They suggest you remove basket (Metal cage behind pump) and discard. Their gasket has a oil dam which I decided not to use. Instead I left basket in place and used gasket I purchased. I don't think either way is very important. Before you connect up vacuum line you need to start engine and pour in small quanity of new engine oil into pump through vacuum line connection. Then stop engine (use manual lever on pump) and reconnect vacuum line.

(By the way you need to remove cooling fan and serpentine belt to remove pump. I don't have radiator guard in place any more so not a big deal, but with gaurd in place it is a pain in the arse because you don't have enough room to get to fan bolts)

Anyway long story short. No more oil leaks and I'm very pleased with myself. Thank you everyone for your help. Especially Phil at Fastlane. Ordered part at 4.15 PM it was here in Michigan for $9.00 the next morning.