Mountain Mule

Ummm, O.k. So here's the deal. When I depress the brake pedal on my 1990 Cherokee Laredo 6 cyl. There is a certain point where I can here hissing. Any further down, it stops, any further up, it stops. Only at one point does this do it. My brakes feel as if they're not getting QUITE enough power to them.
I turn the engine off and depress the pedal with no pressure loss. Any suggestions??? Thanks..

superj

mine hiss the whole time. the hissing is hte engine vacuum pulling on the diaphragm in the booster and is normal. since yours didn't lose pressure when you tested it with the car off, your booster is not bad.

well, when you push on it a few times when the vehicle is off and hold it, did you start it back up and see if the pedal dropped then? that is actually how you test a booster. keep your foot on the pedal and start the vehicle and if the pedal drops then your booster is good.

usually, if a booster is bad, you'll get a hard break pedal too. are you losing brake fluid? even a little bit at a time? maybe your master cylinder is leaking into the booster and filling the diaphragm area with fluid and its only getting proper vacuum at that point?

Mountain Mule

What, do you think, would cause the brakes to feel as if they're not quite grabbing as good as they should? I have to think ahead of time when I'm driving... I get a headache when I have to think..... Pads don't LOOK glazed over and rotors look good too... It seems as if not QUITE enough power is getting to them...

perez1989

It's the brake booster. The diaphram is torn, my Jeep does the same thing. I ordered a new one should get it in next week.

jeeperscreepers92

I had the problem with an old camry. I had a leak and my brakes would barely work. the temporary way to keep it goin is to refill the break fluid every once in a while. and always switch brands. I know,. it is like a huge NoNO and considered a hue mistake but i didnt have the money to pay for the brakes to be replaced. i am a brakes specialist. bvut i never had time to start huntin down the leak and fix it. but it was a temorary fix to get from point A to B for a couple days depenedin on how often i used the brakes. I understand camrys are diffeent from jeeps. but I understand where hes comin from. the booster may infact be bad on your jeep. Or the leak may be in the hose. But the best thing u can do is have it fixed. becuz when my brakes went. i had to push the pedal to the floor before i even started slowin down and sometimes i would slie. Its best to have it checked out and replaced as soon as possible. becuz leaks in the brakes only get bigger and bigger as time gos by and the vehicle in question is being driven more and more. Especially with winter comin up and the roads start to become slick with water and oil. You want to beable to rely on your vehicle to come to a stop when u want it too. Otherwise u might slide right thru an intersection or risk hittin a pedestrian or rearending another vehicle. and as jeeps are prone to rooll. its not recommended you try to turn the jeep as you slide. Becuz 1) you might not beable to correct the slide. 2) you might hit apot hole and that will either flip you or it might destroy your vehicles suspension.