Hissing brake pedal on my Volvo S80?
I Have a 2001 Volvo S80 T6 and for about a month now ive been noticing that the brake pedal makes a hissing noise (like air is escaping from a container noise) when i release it. It progressively moves from hissing only when i release the brake to hissing the whole time im driving and when im braking. The car stops fine. I just got new brake and rotors on the front. Ive read here ( http://volvoforums.com/forum/showthread.php?t=1100 ) that it could be the “diaphram in the brake booster”
does anyone have any ideas what it could be?