Question about 1999 Jeep Grand Cherokee
Heard a hissing noise all of a sudden
It may be a few different things, most of them relating to the brake
booster. It could be a vacuum hose is loose or ripped (a simple fix,
just replace the hose) which would correlate to a hissing noise outside
the car. If there is a hissing noise inside the car it could be a tear
in the booster on the inside of the car (trace the brake pedal up, at
an angle, and then into a rubber 'boot' or 'fitting'. This is called
the firewall by some people. With the car running (but in park) feel
the rubber boot and see if you feel any air releasing, or if the noise
diminishes when you cover certain parts of the boot). A tear
internally means you need to replace the brake booster itself in some
cases. This is a bit trickier to pull off if you don't have the
Here is a picture of a standard booster/master cylinder.
Another (DANGEROUS) option if the booster itself is leaking is to disconnect the hose from the brake master cylinder, and clamp it off/plug the hose. This is the equivalent of having manual breaks, and will require a lot of pressure to engage the brakes (normally you are compressed air assisted by the booster). The only reason to do this is if the tear is large enough that you are losing engine power because of it. This will allow you to get to the next exit, next gas station, or (in some cases) 3 states away.
Posted on Feb 09, 2009
Can you pinpoint where its comming from? like outside of car?under hood?or under dash? does car act or run any differnt when you apply the breaks?like maybe wanting to stall out? or breaks don't work right or low peddel? could be breaks grinding, time for break job? vacume leak to break booster or booster its self. taking a guess its time for breaks. need more info. to determin what the problem is.
Posted on Jan 26, 2009
Tips for a great answer:
Sep 12, 2014 | 1989 Honda CRX
Jun 27, 2012 | Cars & Trucks
Sep 06, 2011 | GMC Envoy Cars & Trucks
Oct 27, 2010 | Ford Ranger Cars & Trucks
Oct 19, 2010 | Chevrolet S 10 Cars & Trucks
Jun 04, 2009 | 2005 Hyundai Tucson
Jan 26, 2009 | 1999 Jeep Grand Cherokee
759 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: