Brake squeal is caused by the high-frequency vibration of brake components (rotor, calipers, and/or pads) in response to excitation from the brake friction process. A significant amount of time and engineering goes into eliminating brake squeal from original equipment brake components.
Brake components are engineered as a complete system—factory-original performance can only be assured when using original equipment brake pads and rotors. When brake squeal occurs, there may be damage or excessive wear on one or more components affecting noise, including the brake pads, the noise-damping shim that is bonded to the brake pad, or the rotor friction surface.
In addition, it should be recognized that high-performance and track-capable brake systems using high-performance pad materials will always be at higher risk for producing brake squeal noise, even when no damage to the components is present.