This is usually caused by worn brake pads. The pads contain a metal plate that acts like a sensor. When the brakes ware down, this plate contacts the rotor. When this occurs, a noise is usually heard coming from the brakes. This is the brake failure mode, and the brakes should be replaced before this occurs.
|The yellow arrow points to the metal plate. Between yellow lines is the spacing with new brake pads.|
|This is the spacing with old brake pads. Notice the metal plate is in contact with the rotor. This is what causes the squeaking sound.|
Rotherforth ESC Fall 2006