How Do I Know When My Brake Rotors Are Worn Out?

Brake rotors must be properly maintained to ensure the safety of vehicle occupants. Every time the brake pedal is depressed, the expectation is that the vehicle will stop smoothly. Brake rotors are worn out or require service when the vehicle will no longer stop quickly and smoothly.

Normal Wear

All brake components wear with use. The brake rotors are subject to wear whenever the brake pedal is applied. The caliper and brake pads squeeze against the rotor and, with repeated applications, metal will naturally wear away. When normal wear erodes enough of the metal, the rotor thickness will no longer meet minimum standards and rotors must be replaced. Thickness standards for each vehicle model vary and must be measured with a micrometer to determine when replacement is needed. Excessive pedal travel or poor stopping may indicate the rotors are worn out.

Warping of the Brake Rotors

Stop-and-start city driving and mountain driving often create a situation where vehicle brakes are in constant use. The friction caused by the constant application of the brakes produces heat. When heat builds up, metal tends to warp. When the metal of the rotors warps too much, the driver will feel a shudder or pulsation in the pedal, indicating the rotors need to be turned on a lathe to renew the surface or be replaced.

Rotor Wear Caused by Brake Pad Failure

Brake rotors will be destroyed quickly when the pad material is not monitored and the pad base metal comes in direct contact with the rotors. This metal-to-metal contact causes deep gouges in the rotor which often can not be repaired through re-surfacing. Prevent this problem by having the pad thickness monitored regularly.