Development of Brake Standards SAE J134 and J135 for Combination of Vehicles

With the advent of increasing numbers of heavier passenger car-trailer combinations, the need for a uniform brake test procedure code and recommended level of performance requirements for such combination of vehicles became apparent. Initial efforts were directed toward a standard of performance for the trailer or towed vehicle brakes only, but as the work progressed a more practical solution evolved in a test code, SAE J134, and performance requirements, SAE J135, for passenger car-trailer combinations. It is intended that light trucks will be considered in a later revision.