So just over a year ago I did the A8 brake upgrade with plain Zimmerman rotors and Hawk HPS pads and all was great until about 2 months ago when I started noticing the front right brake was squealing. Over the next week or two it got progressively worse and I went ahead and went home one weekend and pulled the front brakes off and applied stop squeak. I got some Permatex stuff that really just seemed like high temp rtv. Anyways, I applied that liberally and the squeak went away for the past month until this past week when it's started to come back again.

They don't squeak at all when cold, but after about 10-15mins of driving and warming them up they both squeak like crazy. Also if I wash the wheels they wont make any noise for about a day then its back to squealing when warm. It doesn't make any noise if I'm going down hill or applying medium-hard pressure. They only make noise at very low/light pressure like when I'm in traffic, or when pulling into parking spaces. The thing is, I back into every spot and theyll squeal as I pull forward slowly before reversing and they wont squeal as I back into the spot. Its driving me nuts and I'm actually embarrassed in traffic and when they make noise

I dont overheat them or anything like that and I can still see there is the permatex on the pads.

 

Anybody?

 

Its the pads, performance pads tend to have more dust, and have the tendency to be "vocal" when braking at almost all speeds when hot.
Put some stock A8 pads on it and you won't hear a sound.

 

I know that, but they were silent for a whole year before they started making noise...

 

Its because they are semi metallics, after a while they will break down and relase metal particles that will be pressed between the pad and rotor. Metal on metal makes..........well you get the picture. The answer is to NOT use semi metallic pads.
Do some google searching about semi metallic brake pads and squealing, you will find very detailed answers im sure.

 

^What he said.

Get ceramics if it bugs ya