Brakes making weird noise

I have a 2004 grand prix gt...almost everytime i brake more then slightly or going down a hill, a weird wooping noise almost like a slight grinding sound comes from the front brakes...and after i start to drive again the sound goes away. I had the pads and rotors checked and we found nothing wrong...could it be abs system?...Any ideas boiz would be awesome, thanx, i really wanna figure this one out:banghead:

I have a 2004 grand prix gt...almost everytime i brake more then slightly or going down a hill, a weird wooping noise almost like a slight grinding sound comes from the front brakes...and after i start to drive again the sound goes away. I had the pads and rotors checked and we found nothing wrong...could it be abs system?...Any ideas boiz would be awesome, thanx, i really wanna figure this one out:banghead:

Well id perosnally check the brakes and pads myself, make sure it's ok, then try using some brake silencer and cleaner on the rotors.

You may have a rotor slightly out of round/warped causing the high speed pulsation, or it could be the pad friction material has uneven sized metallic/ceramic particles and one of those is causing the noise.

You may have a rotor slightly out of round/warped causing the high speed pulsation, or it could be the pad friction material has uneven sized metallic/ceramic particles and one of those is causing the noise.Ok thanx alot bro i will go in to get that worked on...is it cheap? should i get new rotors or will they be able to plain em down so there is no uneven thinkness? and what about the pad friction, need new pads?

I think my 98 gtp did this as well, never got around to checking it out, would re-surfacing the rotors do anything?

yea i'd replace because there cheap $20.but thats our cost!! if you go to a shop i'd suggest machining replacing might be costly sand pads if there in good shape or replace good luck

How many miles on the car? If it could be due for brakes, pull off the front wheels and visually inspect them. You may be able to re-surface the rotors, but I would just replace them if they show signs of discoloration or warpage. Don't cheap out on the pads either, as cheap brand pads have lesser quality friction material that can lead to high dusting and noise.

Rich,

Since you mentioned not using cheap pads, do you have any recommendations for type/brand? My '99 GP GT sounds and feels like I have a warped rotor in the front, and it's probably time for pads.

Thanks!

I'm having the same problem in my 04 gt2 at low speeds, could the rotor be glazed over due to heavier braking earlier in the old pads life. I've replaced the pads but the whining is still happening. or should i just replace the rotor.

The 04-up models came factory with ceramic pads, so try to stick with AC-Delco Durastop Ceramics, or Raybestos Quiet Stop is another good choice. Good stopping power, low dust, and no squealing.

sounds good, im gonna try changing the pads first and see if noise goes away, if not new rotors. Where can i bought Raybestos? Canadain tire lol