This document specifies minimum performance and durability requirements for satisfactory vehicle usage@ and it is applicable to wheel cylinder assemblies from commercial production@ after production shipment@ shelf storage@ and remanufacture (factory rebuild). Purpose This document applies to wheel cylinder assemblies used on hydraulically operated@ drum-type brakes of highway vehicles. It covers such cylinders where they are employed in passenger car@ light-duty truck@ bus@ that are up to and including 4500 kg (10 000 lb)@ and like brake systems utilizing motor vehicle brake fluids that conform to SAE J1703@ SAE J1704 or other OEM specified brake fluids.