The causes of rotor warping include manufacturing errors and improper bedding-in of rotors and brake pads. A faulty brake system impairs the functioning of the rotors, leading to warping.
Manufacturing defects on a rotor cause warping. Aftermarket rotors may be of low manufacturing quality, meaning that once installed, the rotors tend to warp, especially if they have excessive run-out measurements. Manufacturing errors may result in rotors with imbalanced structures, which means their weight is unevenly distributed. Exposure to differing operating temperatures causes uneven deposits of friction materials and warping on the rotor.
If the brake system is not functioning optimally, it may strain the front or rear brakes, causing the rotors to heat up. In some instances, a sticky caliper, the mechanism responsible for operating the brake pads, impairs the functioning of the rotors and causes warping. Worn out shocks strain the vehicle’s braking system, increasing pressure on the rotors and raising the risk of warping.
A motorist who fails to adhere to the manufacturer's bed-in instructions upon installation of a new rotor and pad risks distorting the rotor due to uneven transfer of friction material. Bedding-in allows the transfer of a consistent layer of friction material from the pads to the rotor before running the brakes at high temperature.