You know that sound. You're coming to a stop at a red light, with the windows open, and your car begins emitting an ear-piercing wail that causes horrified pedestrians to turn and stare. It's embarrassing, right? More important, it's your car trying to speak with you.
People lose it generally, and think they need a complete brake overhaul now. But honestly? Sometimes it's just dust.
Before you run to the mechanic and throw down $300, try this: find an empty road and do a handful of "bed-in" stops. Go to 40 miles an hour, and then step on the brakes quickly (but not so hard that you slam them) until your speed drops back down to 10 miles an hour. Do this a few times. This usually wipes away the glaze
If the sound remains, this is probably the wear indicator - a small metal tab purpose built to screech when your pads start getting too thin. If you are, don't disregard it. I was lazy once and let it go for another month and wrecked my rotors. A $50 pad slap was on its way to a $400 rotor replacement. Lesson learned: screeching is code for "check me now," not "turn up the radio."