1999 Other Jeep Models hissing noise

BOSSYMAMA

MEMBER
1999 JEEP
6 CYL
4WD
AUTOMATIC
140,000 MILES

I have a 99 grand cherokee and there is a hissing noise coming from the brake pedal and when you push on the brake pedal it stops and as soon as you let off it starts hissing again.

Wednesday, February 13th, 2008 AT 1:03 AM

1 Reply

2CARPRO JACK

MECHANIC
11,533 POSTS

Sounds like a vacuum leak under the dash. Most likely the brake booster, but I would look first to be sure there arent any vacuum lines down there for the cruise control. They would be on the brake pedal assembly, going to a switch if there even are any. If none, then the brake booster is bad