My wife has a 97 S-90 that makes a vacuum leaking noise inside the car when the brake pedal is pushed. Also, the brakes are non-existent and the pedal is hard to push. Smokey, the volvo, has 128,000 miles on her and we have owned her about 2 years. She is turning into a trailer queen (ho ho!) as she had to be towed home due to the brakes. I am assuming that the brake vacuum booster is the cause of the above mentioned issues. I went to the salvage yard and found one manufactured by Bosch dated 2003 from a 95 960 (for $18.50). While removing this one, I noticed an adjuster on the master cylinder end. Would anyone have any information on the adjustment procedure. Also, any other tips would be appreciated. You all have been a great help in the past so, thanks in advance.