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is my brake booster bad?

02-24-2008, 02:43 PM
I have the 97 Jeep Grand Cherokee 4.0L.

For awhile now I have heard a swoosh sound while pressing on the brake pedal, I never thought much of it until recentley.

I was stuck in heavy traffic on the freeway and had to stop frequentley, however my jeep wouldn't always stop quickley, even at low speeds trying to stop suddenly seemed impossible while pushing hard on the pedal, very scary.

The brakes have always been somewhat squishy even after being bled, so I started searching and found this thread...

It sounds exactley the same. I pushed on the pedal while it was running and the swoosh sound was continuous, so I looked under the dash and the rubber seal looks pretty old, the foam in the middle looks to be deteriorated as well.

I guess I just need some confirmation that this is the problem and also what part or parts I need to start looking for so I can get this fixxed soon, afterall I can't go wheeling in the mountains without brakes!

Thanks for any help that is provided.

02-24-2008, 07:14 PM
Hi Dell, it definitely sounds like you have a bad brake booster. I've got the same problem with my Civic-I was trying to bleed the brakes today and could not get the air out. I was hearing a swooshing sound coming from the booster area (kinda sounded like a wet sucking/blowing sound). My neighbor, a former brake technician, said he was 100% certain it was the brake booster. My symptoms while driving are a brake pedal that goes all the way down with very little stopping power. If I pump the brake real fast, pressure will build temporarily, but not for long. So, I would say you've got a bad brake booster. As far as locating parts, I would stay away from junkyard vehicles. They say that vehicles that have sat for a while will have dried out boosters, which are prone to crack and fail. I'd look at Autozone for a new one or Ebay for a cheap remanufactured booster. Good luck with it.

02-24-2008, 07:57 PM
I called autozone and they have the brake booster for $75.00 so I'll pick one up then.

In my Hanes manual it doesn't seem to complicated to swap out... Has anyone done this? or should I pay to have it done, I hate paying mechanics for anything except tranny or internal engine work so if it's easy enough I'd like to do it myself... lemme know thanks.

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