vacuum problem...
 

Hello
Own a 81 300d,160000 miles.This is what happens
-doors lock ok
-problems with shutting the engine
-no power brakes
is it the pump or a leak ...:confused:
please advise
regards z

Sounds like a pretty good leak. Do a search for vacuum leaks, and you will find lots of info on the subject.

There is a checkvalve in the line going to the brake booster. It's one of the yellow ones and has 4 lines going into it. I knocked the center line loose once durin an oil change and had no power brakes and it wouldn.t shut off. I'd say the valve is either bad or one of the lines are loose.

Hey, Flanagan has a picture posted here http://www.peachparts.com/shopforum/diesel-discussion/170372-mystery-vac-line.html
That shows the valve. You can see it best in the second picture just in front of the filter he's holding.

thanks for the input,I will play with it during the weekend
problems come in pairs...my 87 560 sl developed a loud noise when started:eek: could be timing chain
thanks guys

To directly check to see if its the vac pump or the break booster try this:
Hook up your mitvac to the main line that goes from the pump to the booster. Then plug any other lines. Start the car and see if it holds steady or not. It should be reading 20"-25" If yes then both the pump and booster are fine. If no then use a wrenchc to remove the main line from the booster. Then plug the end of the main line. I usually lick my thumb and put it on the hole tightly. If the vac is 20-25 then the pump if fine, and the booster is your leak. If the vac is jumpy or much below 20 than the pump needs rebuild or possibly a replacement.