proportioner valve

I seen on another thread about someone having a problem with a grinding noise when breaking.. Pads are in real good shape. I dont hear it all the time when I do its really quite mostly can hear it when Im in a drive thru or in a alley when Im next to a building (know what I mean you get an echo?) anyways they mention it might be the Proportioner Valve where is that located so I can see if its leaking? I just bought the car and the dealer put a 3 month 3000 mile bumper to bumper warrenty on it so any little thing I want to get fixed. Also is there anything else I should look at that is common on 99 GP's I can check out and get fixed before the warrenty is up? it has 99,000 on it 3800 motor. Any suggestions would be great..

I seen on another thread about someone having a problem with a grinding noise when breaking.. Pads are in real good shape. I dont hear it all the time when I do its really quite mostly can hear it when Im in a drive thru or in a alley when Im next to a building (know what I mean you get an echo?) anyways they mention it might be the Proportioner Valve where is that located so I can see if its leaking? I just bought the car and the dealer put a 3 month 3000 mile bumper to bumper warrenty on it so any little thing I want to get fixed. Also is there anything else I should look at that is common on 99 GP's I can check out and get fixed before the warrenty is up? it has 99,000 on it 3800 motor. Any suggestions would be great..
Brake noise has nothing to do with the proportioning valve, this controls the percentage of pressure distributed to the rear brakes, the noise is something else.. The upper intake on these engine can be problematic regarding the egr passage deteriorating and leaking coolant into the engine. Mysterious coolant losses are the first sign.The 380011 is a very strong engine with normal upkeep.

So any suggestions on what it might be? Only hear it really low speeds. Sounds like the pads are metal to meatal. But they are like brand new... I power washed them out thinking there was dirt or something but no help.

Do you know what brand pads and rotor are currently installed. Most noises when braking are either the pads or the disc rotors. Cheap pads with a high semi-metallic content will give off an annoying grinding or metal to metal sound when braking. Warped, cheap (low grade), worn out or improperly serviced rotors - i.e. not turned down when pads were replaced. The only special consideration for brakes on a Grand Prix is to get quality brake replacement parts and do the work properly.

:iagree: Cheap pads have either big pieces or uneven distribution of the metallic particles in the friction material which will grind or squeal until they wear off. I put ceramic pads on my 99 GT and couldn't be happier. No black dust on my chrome wheels, and no noise.