These specifications cover molded rubber boots used as end closures on drum type wheel brake actuating cylinders to prevent the entrance of dirt and moisture which could cause corrosion and otherwise impair wheel brake operation.

The specifications include performance tests of brake cylinder boots of both plain and metal insert types under specified conditions and do not include requirements relating to chemical composition, tensile strength, or elongation of the rubber compound. Further, they do not cover the strength of the adhesion of rubber to metal in the insert type.

The rubber material used in these boots is classified as suitable for operation in a temperature range of −40 to +120 ±2 C (−40 to +248 ±3.6 F).