Audi Avant S-line AAN turbo quattro 275hp ca.340kkm , ca.30 yo (Pic. 2).
Used to have unique original "UFO-style" brakes (Pic. 1). Those were great: no fading at all, but but the respective rotors are not available any more.
So I had to dump those calipers and to install even bigger brakes from an Audi А8(D2).
Those work fine too, and are even less prone to vibrations, BUT (and it is a big BUT):
they squeak. Pads are OK and high quality. When cold, and when the weather is damp, the brakes dont squeak at all. But in dry (especially hot) weather they squeak like hell when braking. Is there anything one can do about it? Some spray or whatever? Thanks.
P.S. No Akebono pads available for these calipers.
Pic 1: previous UFO-style brakes (typical): https://1drv.ms/i/s!Alv3RQPn1ylAqirkt0yPG3zZG-jC?e=Ea8Ay3
Pic 2: My Audi Avant AAN turbo quattro: https://1drv.ms/i/s!Alv3RQPn1ylAqiugvAevp881KEL7?e=ihSu6I
Wow. I've never seen brakes like that.
A squeak is a sound, and sounds are created by vibration. In this case, the pads vibrate (also known as chatter in the machining/woodwork world). A few things can lead to that ...
- the interaction between the the brake pad linings and the rotor surface. Too much or too little friction. Pads sticking too much. glazed rotors. Contamination. etc. Sometimes it helps to just cleaning everything up with some brake cleaner, or even scuffing up the rotor with some sandpaper. Sometimes changing the pads to a different brand (differences in material), or the rotors, or both can help.
- the system isn't rigid enough. There is to much opportunity for the pads to move, and vibrate back and forth. Some calipers come with shims to take up the gap and decrease vibration. Make sure all caliper bolts and lug nuts are torqued to spec, in the correct order. They sell anti-squeal compound you can put between the pad, and piston, and contact surfaces, and it helps dampen the sound.
