Brakes Worn Pads 

Disc brake pads usually have a piece of metal on them called a wear indicator. When enough of the friction material is worn away, the wear indicator will contact the disc and make a squealing sound. This means it is time for new brake pads. If you neglect your brake pads and shoes, your brakes will ultimately fail. Even before that happens, however, you can cause damage to other, more expensive brake parts, such as rotors, drums and calipers.