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power brake booster

Posted: Wed Jun 28, 2006 2:40 pm
by Decipha
im thinking my power brake booser is going bad simply cuz its the only thing i haven't changed, i've changed the master cylinder, new brake hoses, both rear wheel cylinders, new pads & shoes and my brake pedal still travels about 4 inches before the car even attemps to start slowing.

also i did a little test, i started the car and hit the brake pedal, then i killed it and let off the pedal and pumped it, on the first pump after i released the pedal it got rock solid hard, so im thinking i may have a vacuum leak in my brake booster??? anybody know something i may not?  it keeps its pressure when i hold it down when the car if off though

i also noticed that when i hit the brakes the brake booster moves about 3" inches up, i checked the bolts holding it in and they seem to be tight, could this be another indication that its going bad?

power brake booster

Posted: Wed Jun 28, 2006 2:43 pm
by spacecadetz26
do you hear a swooshing noise when you push the brake pedal?

power brake booster

Posted: Wed Jun 28, 2006 2:52 pm
by Decipha
yup

power brake booster

Posted: Wed Jun 28, 2006 3:07 pm
by spacecadetz26
when its runnign does the idle go up when you push the brakes

power brake booster

Posted: Wed Jun 28, 2006 4:15 pm
by Decipha
no actually it drops, then it goes up but very little

power brake booster

Posted: Wed Aug 30, 2006 3:10 am
by docrodg
Keep the car off and press the brake, hold the pedal down with moderate force and start the engine, it should sink without you changing the pressure on it.  IF it does the booster is likely good.  THen check it again after the engine is off by pumping slowly, it should take more than one pump before you lock up hard and high on the pedal.  If it locks up after one pump then it is probably the check valve for the booster.  The movement is a worry, it shouldn't move like that and could be that the case is cracked.