This sound tells you that it's time to change pads for fresh, thicker ones before the friction material wears completely away. Let it go for too long, and you'll be trying to grip your metal rotors using the metal backing plates of your pads, which aren't very grippy at all and ...
It's a grinding noise that follows you around town - at least it sounds like it's following because the sound is coming from the rear of your vehicle. You only hear it when you use the brakes. You grab a flashlight to check the thickness of the rear pads - but then realize you've...