BRAKE ISSUES - WHAT IS WRONG?
Asked by kjunlade Apr 15, 2015 at 12:30 PM about the 2004 Pontiac Grand Prix GT2
Question type: Maintenance & Repair
This happens often and I have read many creditable information on the web about anit-
lock brake systems and mine seem to do just as they are supposed to (grind and
pulsate). However, when I hit a bump in the road even when the road is dry or when
the road is wet I keep skidding and usually have to swerve to the side so I don't hit
anyone in the back. Yesterday I was going about 10 mph and was slowing down
coming up to a red light and they worked fine then all of a sudden "locked up" and the
car wouldn't stop, good thing the vehicle in the other lane was far enough for me to get
in (even though I cut him off). I have changed the pads on the front and still have to do
the back. I changed the rotor on the driver side as well. The brake dust builds up really
quick on that side.
6 Answers
First of all, when you change brakes you do them in pairs. If you replace brake pads, you do both sides., If you replace rotors, you do both. Is your abs light on all the time? Have you checked the calipers and hoses? The caliper could be locking up, the brake hoses could be collapsing internally. Hope that helps.
I bought the car used in October, since then, had to change the brakes twice and were changed at the same time, however I had to change the driver side a third time. I have not checked the calipers or hoses so I will see about that today if the rain holds up. Thanks a bunch!
migration_dav48 answered 9 years ago
You might either check or have it checked your brake pedal switch cause I have noticed since I had mine replaced on my 2006 Trailblazer, that my brakes even seem to work better I know have better pedal and don't feel spongy... I hope this helps your problems too......
Here's a video of a typical system. As you can see, there are many things that can be malfunctioning. You may have a bad wheel sensor or a bad valve solenoid. It's a tough call. https://www.youtube.com/watch?v=rfzuW8wFpgI But like Stanford said, check all the basic parts first. You may have rusted slides or a piston may not be retracting after brakes are applied.
I'm agreeing with what others have posted. Accelerated pad wear which you most certainly have is very likely caused by bad calipers. I can't think of anything else that would cause that. Calipers are inexpensive and are a sensible replacement on an older car anyway. I've had similar brake failure issues at very low speed like you have. Check wheel bearings and possibly even axle shafts. Tolerances for the ABS system are very small. Bad bearings seem to throw things out of spec just enough send confusing messages to the computer and make the brakes operate a bit erratically. Both times when I replaced bearings and axles the problem went away.
