Brake noise

I often hear, "Why do my brakes make noise when the weather is wet?"

The simple answer is, that your brakes are acting like a musical instrument.

Much like a violinist rosins his bow to make just the right vibration with the strings, so the brake pads have a chemical in them like rosin, that if just the right amount of pressure is put on the rotors, the rotors will vibrate at an audible frequency, the suspension will be the sound board, and a musical note is made, however irritating it may be.

To get rid of these awful sounds your brakes make, drive only in very dry conditions, or have the resin removed from the brake rotors and the brake pads re-burnished.  One way is free, the other costs about $150 to $200 per axle.