typically when my ac is on(engine revs higher), and a while pressing the brake pedal at a certain position, i get a duck quack like sound. if i find the right brake pedal position, i can maintain the quack sound constant. i'm guessing i may have a vaccum leak somewhere......also when my car is off, the vacuum bleeds off and the brake pedal is stiff.

i never did have the brake recall done on my car.

 

ok, the car had been sitting for a while until recently. i took the car for a spin tonight, and the noise was only there when the brakes were warm, and while moving. my front pads are making the noise when the brake pedal is partially pressed. i just need to brake harder i guess. lol

 

Funny you mention this. I noticed a "quack" sound coming from my brakes after a drive as well. It seems to sound like it is coming from the rear brakes. Only when braking in reverse. I did have the Brake Recall performed and it seemed to happen after that. Funny thing is when I took it to the dealer on the next service, they could not replicate the issue. I hear it when backing in to my spot at work and in the garage. Not sure what it could be.

 

If you never had the brake vacuum pump recall done, I would suggest getting it done.
I had my power-assist brakes quit on me before the recall was issued, and nearly had a few wrecks because of it.