User manual BENDIX PP-7 TRAILER SUPPLY VALVE

[. . . ] CONTROL SPIROL PIN (1) THIN NUT O-RING (19) BODY INLET & EXHAUST (16) VALVE RETAINING RING (10) SEALING RING (3) O-RING RETAINER (11) INLET & EXHAUST (14) VALVE SPRING SPRING (7) LOWER BODY PISTON (6) O-RING (8) O-RING (5) END PLATE (4) FIGURE 2 - SECTIONAL 1 SD-03-3617 PP-7TM Control Valve TRACTOR DUAL AIR BRAKE SYSTEM TP-3TM Tractor Protection DS-1 SB-3 Park Control SR-1TM Spring Brake Valve SB-3 E-7TM Dual Brake Valve LQ-3TM Valve Double Check Valve LP-3TM Low Pressure Indicator Modulator #2 Service Reservoir Supply Reservoir #1 Service Reservoir SB-3 R-8TM RELAY VALVE SB-3 FIGURE 3 - PIPING DIAGRAM PP-7TM VALVE LESS THAN 50 PSI SYSTEM PRESSURE Park Control Valve To Parking Brakes #1 Service Reservoir Supply Port Plunger Inlet & Exhaust Exhaust Vent To Tractor Protection Control Inlet and Exhaust Double Check Valve #2 Service Reservoir Control Port Exhaust Port Control Piston FIGURE 4 - PP-7TM TRAILER SUPPLY VALVE LESS THAN 50 PSI SYSTEM PRESSURE 2 PP-7TM VALVE SYSTEM FULLY CHARGED Park Control Valve To Parking Brakes #1 Service Reservoir Supply Port Plunger Inlet & Exhaust Exhaust Vent To Tractor Protection Control Inlet and Exhaust Double Check Valve #2 Service Reservoir Control Port Exhaust Port Control Piston FIGURE 5 - PP-7TM TRAILER SUPPLY VALVE SYSTEM FULLY CHARGED after it is depressed and it will remain in until supply air pressure falls below 40 P. S. I. or until the valve is manually actuated. OPERATION - LESS THAN 50 P. S. I. SYSTEM PRESSURE With less than 50 P. S. I. system air pressure, the button of the PP-7TM valve will be out and the park control valve will not deliver air to the control port of the PP-7TM valve. [. . . ] Note at what pressure (descending) the button of the PP-7 TM valve pops out and exhausts the tractor-trailer supply line. If the PP-7TM trailer supply valve fails to function as described or if leakage is excessive, it is recommended that it be returned to the nearest Bendix authorized outlet for a factory remanufactured valve. If this is not possible, the valve should be repaired using only genuine Bendix replacement parts, in which case the following should prove helpful. NOTE: Maintenance piece number 287367 kit is available for the PP-7TM trailer supply valve, which contains all the necessary parts to completely repair it, from any authorized Bendix outlet. Chock the vehicle wheels and drain all air system reservoirs completely. Disconnect all air lines leading to and from the PP-7TM valve and mark them for proper reconnection. Using a drift pin punch, remove the spirol pin (1) Fig. 2 which secures the button to the plunger. Using a 1-5/16 inch wrench, remove the special thin nut which secures the PP-7TM valve to the panel and remove the valve. Mark the upper and lower body halves to show their relationship to each other. Remove the two 1/4 inch-20 cap screws, that secure the lower valve body to the upper valve body, using a 7/16 inch wrench. Remove and discard the square cut sealing ring (3) between the upper and lower body halves. Remove the end plate (4) and o-ring (5) from the lower body and discard the o-ring. Remove the control piston (6) and piston return spring (7). Remove the large (8) and small diameter o-rings (9) from the piston and discard them. Remove the internal truarc retaining ring (10) from the lower body. Remove the o-ring retainer (11) and remove and discard the o-ring (12). Remove the inlet exhaust valve (13) and return spring (14). 5 OPERATING AND LEAKAGE CHECKS To perform the following test, an accurate vehicle test gauge installed in a spare hose coupling is required. The vehicle dash gauge(s) should be checked for accuracy against the test gauge prior to making these tests. Block or hold the vehicle by means other than the service air brakes. With the PP-7TM trailer supply valve button out and the parking control valve in the exhaust, or brakes applied position, build the air system pressure to governor cut-out. Apply a soap solution to the exhaust vent and the plunger stem of the PP-7TM valve to check for leakage. [. . . ] Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Torque the special hex nut to 30-40 inch pounds. Install the square cut seal ring (3) in the upper body. Install the large (8) and small diameter o-rings (9) on the control piston (6). [. . . ]