Thread: Random brake failure

Hey everyone,
Got a friend who called with a problem with his 2004 Pontiac GP 6 banger(no SC). When he goes to slow down at a light or turn, the brakes get hard and go to the floor. He hears a "Motor" running when this happens. I asked if he felt pulsating in the brake pedal and he does not. There is no ABS light on either. Any ideas? I am thinking maybe a wheel sensor but not sure.

i have this same problem slightly. i slow the car down and it gets to about 10 mph and you hear a groaning sound but the pedal doesnt drop completely. it dont happen all the time so im pretty sure its the abs pump. and my brake fluid is full by the way

With the brakes getting hard sometimes it almost sounds like the booster is bad. Usually when the MC lets go the pedal will go to the floor and might build pressure if you pump it a few times.

And yea, the ABS pump is probably freaking out, hence why it is running a lot. IIRC shops can run a test on the ABS parts of these cars. May be worth the $80 diag. fee to find out before he slams into someone.

He has checked for leaks everywhere. MC is dry all around it. Fluid is full. All brakes lines are dry and front caliber brackets are tight. I though maybe a booster but this is a random occurence. I think he is going to bring it in to get it scanned. Thanks for the replies everyone..