Mechanics

04 FRONT BRAKES LOCKING UP

2004 Oldsmobile Alero • 4 cylinder FWD Automatic • 110,000 miles

2004 OLDS ALERO NO ANTI-LOCK OPTION; FRON BRAKES KEEP LOCKING UP.
So far; I replaced the
1) master cylender
2) booster
3) one caliper (driver side)
4) one brake hose to driver side caliper
5) brake pads
6) rotors (now already warped from locking up)
The car appeared to be ok for about 10 days, then the pedal started getting "hard", and the front (both) calipers locked up again!

I'm so frustraited, and out of options! Thanks in advance!
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ARTJPET
August 14, 2011.




Your car has a split-diagonal hydraulic system so each front brake works on a different part of the master cylinder. If both front brakes are locking up, the brake fluid isn't releasing back to the master cylinder. You can prove that when they're locked up by cracking open the bleeder screws. Even easier, loosen the lines at the master cylinder. If that makes the brakes release, the next time it happens, loosen the two nuts holding the master cylinder to the booster. If they release that way, you have the wrong push rod adjustment or the brake light switch is holding the brake pedal from fully releasing.

If cracking the lines open releases the brakes, suspect the brake fluid is contaminated with petroleum product such as engine oil, transmission fluid, or power steering fluid. That will cause the rubber lip seals in the master cylinder to swell and grow past the fluid return ports, blocking them off and keeping the brakes applied. The ONLY acceptable repair for that is to replace every part in the system that has a rubber part that contacts brake fluid, and you must flush and dry all of the steel lines. Thank goodness you don't have anti-lock brakes, but that will still be a very expensive repair. Ten days is about right for that contamination to affect your new master cylinder.
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Caradiodoc
Aug 14, 2011.
Thanks; your answer gives me 2 more solid leads. I appreciate your sharing of your time and knowledge! I can't afford to replace this car, and it is important that I can get it running!
Thanks again!
ARTJPET

Tiny
ARTJPET
Aug 14, 2011.

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