My brakes on my S4 squeel at 1 to 5 mph ,I have removed the pads cleaned the calipers ,the pads look in good shape although I don`t know their age ,I have put some copper slip between the back of the pads and the anti squeel shim.
test
sounds like ou’ve done the faoured remedy there. Could be your calipers are starting to sieze, not free off after braking. I’d go for new pads and see if that cures it.
regards
Mark
Try putting a 45 degree chamfer on the leading edge of the pad with a file. That often helps reduce low speed light application pressure squeal.
regards
Rohan