Abstract: The invention provides a noise-damping friction pad system, and the use of such a system in disc brakes, where the coefficient of friction of the outer friction pad differs by at least 2% from the coefficient of friction of the inner friction pad to reduce brake squeal noise. The inner friction pad and outer friction pad may each comprise at least one cross slot though the surface of each pad that is not in contact with the backing plates to further reduce brake squeal noise. The friction pads may be made of a ceramic composition a lomet composition, or one friction pad may be made of a ceramic composition and the other friction pad made of a lomet composition.

Abstract: The present invention is a noise-damping shim system for use with disc brakes to dampen vibrational noise, or brake squeal. The system includes an inner shim, or noise damper, for placement between the piston and inner brake pad backing plate, where the outer surface of the inner shim adjacent to the piston has a relatively low coefficient of friction, and an outer shim, for placement between the caliper housing and outer brake pad backing plate, where the outer surface of the outer shim has a relatively high coefficient of friction. The outer surface of the inner shim may have a coefficient of friction of between 0.05 and 0.4. The outer surface of the outer shim may have a coefficient of friction of between 0.5 and 1.0. The shims may be single layer or multi-layer and composed of metal and elastomeric material or fabric, optionally with coatings such as polytetrafluoroethylene.