Squeaking brakes when wet

Elf20

When the front brakes get wet (rain, snow) they squeak/screech as you back up and apply them. In dry conditions, there is no noise of any kind. Our trusted mechanics cannot find what is causing the issue. Does anyone have any ideas to solve the problem? Thanks.

thecardoc3

Contamination of the brake pad material can do this, but there is very little in the way of inspecting the brakes that can reveal the cause. Some common contaminants are tire shine, oils, or greases that get onto the rotor and get transferred to the pads. Once contaminated there may be no solution beyond replacement even though other than the noise the brakes were properly. Technically speaking water/snow is itself contamination of the pad material. If the sound goes away after the first few brake applications and no other symptoms are noted, then it would be OK to just accept that it is a tendency of the pads and rotors. That means of course that you could replace the brakes and rotors and still end back up with this symptom. One thing that has changed recently is the reduction of copper in the brake pad material. That has been associated with an increase in brake noise in some cases. If these pads are the reduced copper compound ceramics, then switching to a set of pads that still have the older specification material might help as long as you can find them,