User manual BENDIX AIR HORNS AND VALVES

[. . . ] Disconnect the air line to the air horn. Remove air horn mounting nut and remove horn. Remove mounting bolts and remove horn valve. OPERATION The horn is operated by pulling down on the lever of a hand-operated horn valve or pushing down on the button of the foot-operated horn valve. This action pushes down on the supply valve stem in the horn valve and opens the supply valve. [. . . ] Remove the eight nuts and bolts holding the two covers to the body. Remove the diaphragms from the body of the air horn. Remove the spring contact, springs, and spring assemblies from the covers of air horn. Remove the spring cage from the valve body. Remove the valve stem from the valve body. Remove the strainer and spring from the spring cage. TEST OF REBUILT AIR HORN AND HORN VALVE Both operating test and leakage test must be made after rebuilding or repairing an air horn or horn valve. If the air horn does not operate satisfactorily, adjustment of the spring load behind the diaphragm can be made by turning the adjusting screw in the cover. Before attempting to turn the adjusting screw, loosen the adjusting screw lock nut. Be sure to tighten the adjusting screw lock nut after any adjustment. WARNING!PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH: When working on or around a vehicle, the following general precautions should be observed at all times. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels. Stop the engine and remove ignition key when working under or around the vehicle. When working in the engine compartment, the engine should be shut off and the ignition key should be removed. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated or electrically charged components. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools. If the work is being performed on the vehicle's air brake system, or any auxiliary pressurized air systems, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle. If the vehicle is equipped with an AD-ISTM air dryer system or a dryer reservoir module, be sure to drain the purge reservoir. Following the vehicle manufacturer's recommended procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle. Never exceed manufacturer's recommended pressures. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted. [. . . ] If damaged, they should be repaired or replaced. Be sure the valve stem does not bind when inserted in the valve body. ASSEMBLY NOTE: When using pipe thread sealant during assembly and installation, take particular care to prevent the sealant from entering the valve itself. Apply the sealant beginning with the second thread back from the end. Install the spring contacts, springs, and spring assemblies to the covers. [. . . ]