Hello All -

A few Brake Booster Questions. I just noticed today on the way home my 1992 240 wagon(191,000 - automatic) a air leaking noise in the cabin when I depress the brakes. Fine for quick stops...but if I keep my foot on the brake pedal the car starts to studder.

I did some online searches on the brickboard and checked the 700/900 FAQ's and think the problem must be the brake booster. Or a leak in the brake booster diaphram. The sound is mostly in the cabin when brake pedal is depressed.

THe 700/900 FAq's say --- "The pedal should sink about 1/2" as the vacuum does its work. If nothing happens, carefully pull the white vacuum check valve on the front of the booster out of its seal and see if there is vacuum at the servo/booster side of the valve with the engine running. If you don`t have vacuum there, either the valve is stuck shut, or you have a blockage in the plumbing. You should be able to get the valve as a separate part."

The pedal sinks a little...I tried pulling the white vacuum check valve out of its housing while the car was running and the engine shut down immediately? any thoughts....advice??

Thanks....