Brakes making thumping bumping knocking noise....

[PiLOTLiTE]

Sometimes when I hit the brakes, mostly under light pressure, I hear this knocking/thumping noise coming from them. I can't tell whether is front or rear. I can feel it in the brake pedal and it seems to rattle the car a little bit. Sometimes it is also louder than others as I've had a passenger notice it as well.

So what's up? Pads and rotors are all less than 3k miles old. Brake fluid was flushed at the same time, there is no air in the system. I have heard of something called a "sticky caliper" being able to cause a knocking noise from the brakes. Is that just what it sounds like...the caliper sticks open or compressed? How can I fix that?

Any other suggestions?

[Skapimp]

My money's on a warped rotor.... What type of rotors do you have? stock?

I've had my rotors replaced 3 times from the GM dealer, after my warranty is over, I'm going aftermarket.

[PiLOTLiTE]

KVR blanks less than 3k miles old. And I had them turned before they were first installed to make sure they went on flat.

[Leviathan1994]

you'd be suprised, i had the same problem and the whole assembly that holds the caliper was worn, so the caliper was basically vibrating. Hard to explain, but i used a welder to replace the worn metal areas.

[Leviathan1994]

seems to hold up fine so far, no more knocking sounds [img]smile.gif[/img]

[O2Bsogood]

I had the same problem with my Z28. it would make a thumping noise from the rear. I replaced my pads and rotors and it quit. You might just want to double check and make sure something isn't loose somewhere.