Other day my daughter mentioned she was hearing a 'hissing' noise in her 960 when she puts on the brakes. Of course, first thought was worn pads - checked out fine. I did test drive the car and did not notice anyhing.

Last night she mentioned that the brakes were really hard to push down and stop the car. I forced her to drive her brother's car to work today and promised I would leave work early and check them out. Well, yes, I experienced it myself.

When the brakes are applied the 'hissing' is noticeable. Vaccuum lines to brake booster seem okay and the noise is mostly audible from inside the compartment right under the drivers side. When the pedal is depressed the noise is there - pedal released noise goes away. Also, when the pedal is depressed the engine begins to idle roughly - smoothing out when released. I have checked around and almost no place in Albuquerque has a brake booster available (have not checked with the dealer but one place I checked mentioned $400+ dealer price). Mechanic said that it would be about $325 for the booster and $150 (1+ hours labor), Did find a booster for $150 at local parts store but would take about 5 days to get it here.

Question - in everyone's opinion is it the brake booster? Are they hard to change out? Knowing that it is part of the brake system (and my daughtrer is driving) should I go ahead and have the mechanic replace it?

As always - Many Thanks - Ted in Albuquerque

1996 960 with 138,000 miles