Have you checked out the vacuum pump? A torn diaphragm can allow oil into the booster, destroying it. It would cause the symptoms as you describe. The rebuild kit is cheap and not too difficult. A disposable fuel filter added in the vacuum line will reveal oil in the system. Booster can be tested simply with a Mity-Vac or other vacuum tester.
I made a homebuilt tool to start the impossible-to-reach nut out of a piece of copper tubing long enough to reach in and a short piece of rubber hose on the end of the tubing to grip the nut. Greg Fiorentino '85 300SD '80 240D 4 spd. manual '79 300DT (with new crate engine) '95 and '97 Crown Vics -----Original Message----- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Rich Thomas Sent: Saturday, March 07, 2009 3:39 PM To: Mercedes Discussion List Subject: [MBZ] I am stupid So about a year ago I put a ("new") used brake booster on the 300TD after spending a lot of time chasing a no-brake-boost problem, and finally decided it was the brake booster after huge amounts of effort on that. Put on a new one and it was fine. So a few weeks ago same problem, and no shutoff, I figured the used booster I put on had crapped out too. Ordered one from the list mom, put it on last weekend, still no brake boost. sh*t. So today I put the previous one back on and started chasing vac problems again with the vac meter, and by isolating things it seems to be related to the lock system (they have never really worked) or something else not very critical, maybe in the HVAC system (which is not working either for some time. I plugged off one tee going to the locks, have a bit better vac now but still not what it should be, and the car will shut off when I rev it a bit. Brakes seem to be OK, but I gotta bleed them now, again. So Occam's razor proves correct once again, I should have taken a look at that first. But I am really good now at changing brake boosters and master cylinders, in particular that last nut way up under the pedal bracket that you have to contort to get at. --R _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
