Development of Cold Noise Brake Insulator Solutions

The environmental effect on brake system noise characteristics has introduced increased expectations in overall performance as well as associated challenges in the design of brake insulators that can provide optimal noise control within specific temperature extremes. The condition of cold noise brake squeal which is classically defined between 0 to 50C (pad lining temperature) and environmental conditions as low as -50C depending on regional applications has become a major part of customer requirements. This is evident by the proliferation of vehicle and dynamometer test validation protocols (e.g. Minneapolis City Traffic (MCT), GMW 14591, Ford Cold Noise Procedure (CTEP 420), J2521, Federal Mogul (FM204B)) which devote a significant part of the cumulative brake squeal occurrences within the cold noise regime.

This paper discusses the theoretical basis and unique aspects of cold noise brake squeal generation with respect to the source excitation via the brake lining/rotor interface friction effect, system response and the influencing factors of the brake insulator. The technical approach in formulation and construction of the insulator design are discussed with reference to specific application examples.