Swell, Growth, and Dimensional Stability of Friction Materials and Noise Insulators when Exposed to Elevated Temperatures
This performance standard specifies a universal method of measuring the dimensional change of friction materials to determine the effects of temperature. The test applies to both, disc and drum type linings commonly used in hydraulic and air brake systems for automotive or commercial vehicle applications. This standard describes two main test procedures. Method A, where the friction material is in contact with a heated surface to simulate the heat input to the pad that occurs during actual usage. Method B uses an oven to heat the freestanding material and is an approximate procedure requiring less instrumentation. Method A is recommended for disc brake pad assemblies, noise insulators, or flat coupons; while Method B is recommended for curved drum brake linings.
Rationale: This document is reaffirmed until new technologies or feedback from users deem a revision appropriate. The committee confirms the information is still valid within the scope of the document.