99svtvenom

So frustrated with this car, I put in a new brake booster because the old one was rock hard and was garbage. I went and picked up a new brake booster, installed it and took it for a test drive and the pedal is still rock hard! There is plenty of vacuum being pulled from the intake so I have no idea what the deal is here.

When you push the pedal you can here a big woosh of air and then no more air after that, as soon as you can hear no more air (after about and inch or so of pushing the brake) the pedal is rock hard and barely stops the car. Is there something I need to do or is this bran new booster bad? If someone could tell me what to do or anything I should try I would greatly appreciate it.

deanshark

Is there a clog somewhere so it's not letting the fluid flow? I had a problem like that with my old Grand Prix. What I did was I bled the brakes backwards, toward the master. I used this vacuum pump I rented. This one is from Autozone, Idk if they rent it; http://www.autozone.com/autozone/acc...er=988888_0_0_

99svtvenom

Well I have been reading a bit and went outside and did a little test. I pumped up the brakes with the car off and they got somewhat stiff, I then started the car and they did not move to the floor at all (they stayed stiff). Does this point to a bad "new" brake booster? Or do you still think blockage?

PureDrifter

iTrader: (10)

honestly it sounds more like you didnt hook up the vacuum lines properly...

steve2006

I agree sounds like you are missing vacuum, did you check the non return valve in the servo vacuum hose and is the hose securely attached to the servo and the intake at the other end, is the hose in good condition?

python

iTrader: (4)

turn the engine off and pump the pedal a few times,push and hold the pedal with slight but steady pressure then start the car..the pedal should drop a little bit.
or
turn the engine off and pump the pedal..the pedal should rise with each pump

steve2006

He's already done that and the pedal doesn't fall slightly when the engine is started

python

iTrader: (4)

bad booster if he has everything hooked up correctly and the hose isnt collapsing

deanshark

When you pulled the master, did you need to unhook the brake lines which would put air in the system? If so, did you bleed it or are there any leaks?
This is from my 93 manual troubleshooting, Hard pedal but brake inefficient;
1) brake system (fluid leaks)
2) brake system (Air in)
3) brake pads (worn)
4) pad (cracked or distorted)
5) pad (oily)
6) pad (hardened)
7) disc (scored)
8) booster push rod (out of adjustment)
9) booster system (vacuum leaks)

python

iTrader: (4)

the wooshing sound makes me think the booster is bad

deanshark

+1 and I was also thinking bent push rod.

python

iTrader: (4)

im curious as to where he bought the booster...also ive never heard of them failing on the LS

99svtvenom

I'm pretty certain that everything is hooked up properly, there are only a couple things that hook up to the booster (master cylinder and the vacuum hose). I have the vacuum line hooked up and the hose does not collapse and it does pull good vacuum from the intake.

I also bought the brake booster from KOI auto parts which is just a local parts shop around the tri-state area (usually pretty good stuff).

Under the manual procedures that were stated above, what is the booster pushrod adjustment? Could that be anything worth looking into?

python

iTrader: (4)

no..as it has nothing to do with the air sound u r hearing..u have a bad booster. i would rather put a used one on from a junk yard than a rebuilt one from china

billydpowe

iTrader: (1)

first, have you tried to bleed the brakes?? RR-LR-RF-LF did you get good fluid flow from each wheel?? if not, you may have a faulty master cylinder, just flowing to the front or rear.... hard to stop a car like that...