Well I got a 96 4WD that my wife has had since before we got hitched. Its now my daly driver and its has some crappy brakes. I have narrowed it down to the booster being bad. So far I get vaccum through the oneway valve at the booster and I get no pedal pressure buildup when depressing the brakes and starting the car. So there is deffinatly something wrong with this thing especially since I know how these gm systems are suppose to work since I use to own a zr2.

Another thing is that when I have the car idleing and mash the brakes the engine wants to hesitate. So what I wanna know is does this sound like an obviouse booster failure? Im tight on cash and dont want to waste some money on parts I dont need yet. Thanks!

 

The first thing I would do is to bleed the brakes. If you get power assist, the booster should be fine. If the pedal is harder than a rock, then your booster has issues.

 

Well last year when I replaced the front pads I tried to bleed the brakes but was having issues. With 4-wheel anti lock brakes is bleeding the brakes the same as a non abs equiped vehicle? if so then I got other issues.

 

I never had any trouble bleeding the brakes on my Bravada, but I used my vacuum bleeder which pulls the fluid through at a slower rate than pressing on the pedal. But that comes with it's own complications as far as sealing the bleeder... I'd start off doing it the old fashioned way and just move around to various wheels if you find that a check valve closes off somewhere in the system. Just make sure to keep the master cylinder full!!

 

Sorry for hijacking this thread but I also have a question about the brake booster in my '97. How can you tell if the booster is bad? My '97's brake pedal requires more force than all other cars I've owned. I remember from years ago a way of checking the booster was to push on the brake pedal as the engine is starting. If the pedal goes to the floor then the booster is good. I did this and the pedal will go to the floor with minimal force on the pedal. With the engine running, the pedal travel is normal, that is it does not go to the floor. Also, with the engine off, I can pump the break pedal about three times, each time hearing air hissing out. After that the pedal becomes very hard, harder than it does with the engine running. I assume this is correct because pumping the brakes with the engine off will eventually evacuate any stored air in the booster.The brakes work OK, but the power assist seemsweak. Is this just the nature of the beast or is there something I'm missing.
Thanks

 

ok i just changed my brake booster. only took 4 hours but i also changed the three spark plugs on that side also I recomend doing that cause everything is out of the way. the brake booster will make your car kinda sputter cause of the vaccum. if it is really hard to press brakes its definetly the brake booster. brake booster cost about 100.00 just buy it brand new its so worth it.

 

I have a similar problem....

When I'm going to stop and push my foot down on the pedal, the first time it almost goes to the floor and the parking brake light comes on. If I pump it once then put pressure on the pedal it has normal pressure and the truck stops easier. I have had the brakes bled and it didnt help. What else could it be?