1.1 ,These test methods are intended for use in testing the conventional types of hose employed for the operation of air brake and vacuum brake systems,2 either on a single motor vehicle or as connecting or transmission lines in a combination of vehicles. The hose may be assembled with suitable metal couplings or may be as fabricated for use with detachable fittings. The term “,rubber”, as used in these test methods includes synthetic compounds as well as compounds of natural rubber.