User manual BENDIX E-8P

[. . . ] 1 OR PRIMARY CIRCUIT PORTION When the brake treadle is depressed, the plunger exerts force on the spring seat (26), graduating spring (23), and primary piston (22). The primary piston, which contains the exhaust valve seat, closes the primary exhaust valve. As the exhaust valve closes, the primary inlet valve is moved off its seat allowing primary air to flow out the No. 2 OR SECONDARY CIRCUIT When the air pressure on the delivery side of the relay piston (20) approaches that being delivered on the primary side of the relay piston, the relay piston moves closing the secondary inlet valve and stopping further flow of air from the supply line through the valve. [. . . ] Remove the brake valve and treadle assembly from the vehicle by removing the three cap screws on the outer bolt circle of the mounting plate. The basic brake valve alone can be removed by removing the three cap screws on the inner bolt circle. DISASSEMBLY (Figures 4, 5 and 6) 1. If the entire brake valve and treadle assembly was removed from the vehicle, remove the three cap screws securing the treadle assembly to the basic brake valve. Remove the screw (9) securing the exhaust diaphragm (10) and washer (11) to the exhaust cover (12). Remove the four screws that secure the exhaust cover (12) to the lower body. Remove the secondary inlet and exhaust valve assembly (13) from the lower body. Remove the four hex head cap screws securing the lower body to the upper body and separate the body halves. For E-8PTM valve only: While applying thumb pressure to the primary piston (22), lift out and up on the three lock tabs of the primary piston retainer (15). For E-10PTM valve only: While depressing spring seat (7), remove retaining ring (8). Caution: Before proceeding with the disassembly, refer to Figures 3 and 4 and note that the lock nut (16) and stem (17) are used to contain the primary piston return spring (for E-8PTM valve: 23, for E-10PTM valve: 6), stem spring (19), and the relay piston spring (21). The combined force of these springs is approximately 50 pounds and care must be taken when removing the lock nut as the spring forces will be released. It is recommended that the primary piston and relay piston be manually or mechanically contained while the nut and stem are being removed. Using a 3/8" wrench, hold the lock nut (16) on the threaded end of the stem (17). Insert a screwdriver to restrain the stem, remove the lock nut (16), spring seat, (18) and stem spring (19). Remove the primary piston (2) from adapter (1) and o-ring (34) from the primary piston (2). SERVICE CHECKS OPERATING CHECK Check the delivery pressure of both primary and secondary circuits using accurate test gauges. Depress the treadle to several positions between the fully released and fully applied positions, and check the delivered pressure on the test gauges to see that it varies equally and proportionately with the movement of the brake pedal. After a full application is released, the reading on the test gauges should fall off to zero promptly. It should be noted that the primary circuit delivery pressure will be about 2 PSI greater than the secondary circuit delivery pressure with both supply reservoirs at the same pressure. Important: A change in vehicle braking characteristics or a low pressure warning may indicate a malfunction in one or the other brake circuit, and although the vehicle air brake system may continue to function, the vehicle should not be operated until the necessary repairs have been made and both braking circuits, including the pneumatic and mechanical devices, are operating normally. Always check the vehicle brake system for proper operation after performing brake work and before returning the vehicle to service. LEAKAGE CHECK 1. Coat the exhaust port and body of the brake valve with a soap solution. If the brake valve does not function as described above or leakage is excessive, it is recommended that it be replaced with a new or remanufactured unit, or repaired with genuine Bendix parts available at authorized Bendix parts outlets. [. . . ] Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition. For vehicles with Antilock Traction Control (ATC), the ATC function must be disabled (ATC indicator lamp should be ON) prior to performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving. GENERAL SAFETY GUIDELINES 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. [. . . ]