Brake discs (also called rotors) are those all important parts of the brake system that are squeezed by the brake caliper and brake pads when the brake pedal is pressed, which, in turn, slows the vehicle. Brake discs need to be inspected regularly and replaced for the vehicle to brake effectively. Discs wear out over time and can also become warped. If they become warped, the steering wheel and suspension will shake and vibrate when the brakes are applied.
Dirt and Debris on the Rotor
If dirt and debris become trapped between the brake disc and the brake pad, they can eventually cause the disc to warp. The dirt begins to eat away at the metal on the brake rotor, causing it to become warped. This can be due to a wheel replacement where dirt becomes trapped on the brake rotor.
Sudden Temperature Changes
One cause of warped brake discs is a sudden temperature change or excessive temperature applied to the rotor, which can cause the metal of the rotor to expand and contract. This can occur if the brakes are used repeatedly and aggressively, causing them to overheat. Conditions where this may occur include driving the vehicle down a steep grade, where the brakes need to be applied continuously to keep the speed of the vehicle under control. This can also occur if the vehicle is being driven on a racetrack or at high rates of speed.
Worn Brake Pads
Brake discs can also become warped if the brake pads on a vehicle are not changed as part of regular maintenance and are allowed to wear down to the metal backing plates behind the brake pads. The metal then begins to rub against the metal of the brake pads; this, in turn, scores and potentially warps the brake discs due to excessive heat.