Brake Pad Burnishing
The process of breaking in new brake pads and rotors by performing controlled stops to build up a transfer film.
Brake pad burnishing, also known as bedding-in, is the crucial process of mating new brake pads to new or resurfaced brake rotors. During this break-in period, a thin, even layer of friction material (called a transfer film) is deposited from the pads onto the surface of the rotors. Proper burnishing ensures optimal stopping power, reduces noise, and prevents rotor warping.
The burnishing procedure typically involves performing a series of controlled decelerations from moderate speeds (e.g., 30 to 45 mph) down to around 5 or 10 mph without coming to a complete stop. This generates a gradual and even heat buildup in the braking components, allowing the friction material to transfer chemical compounds to the rotor face. Allowing the vehicle to sit with the brakes clamped hot can cause uneven deposits, leading to brake judder.
Failure to properly burnish new brakes can result in glazed pads, severe brake squeal, and uneven pad wear. Glazed pads have a hard, glassy surface that reduces coefficient of friction and stopping efficiency. If a driver experiences pedal pulsation shortly after a brake job, it is often due to irregular pad material transfer caused by improper initial burnishing.