User manual BENDIX R-12DC DBL CHECK RELAY VALVE

[. . . ] The R-12DCTM relay valves are designed for either reservoir or frame mounting. For ease of servicing, the inlet/exhaust valve can be replaced without the need for line removal. CAP SCREW SECONDARY SERVICE PORT RELAY PISTON VALVE RETAINER INLET EXHAUST VALVE DOUBLE CHECK DIAPHRAGM RETAINING RING EXHAUST PORT SPRING GUIDE FIGURE 2 - R-12DCTM RELAY VALVE WITH BIASED DOUBLE CHECK SECTIONAL VIEW 1 SD-03-1068 OPERATION APPLICATION Under normal conditions, the internal biased double check valve assures that the primary service signal controls the valve. Air pressure delivered to the primary service port enters the small cavity above the piston and moves the piston down. The exhaust seat moves down with the piston and seats on the inner or exhaust portion of the inlet/exhaust valve, sealing off the exhaust passage. [. . . ] A warranty may be voided if intrusive maintenance is performed during the warranty period. No two vehicles operate under identical conditions, as a result, maintenance intervals may vary. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 DESCRIPTION VALVE COVER VALVE SPRING CHECK VALVE GUIDE CHECK VALVE O-RING DOUBLE CHECK COVER O-RING O-RING RELAY PISTON VALVE BODY INLET & EXHAUST VALVE VALVE RETAINER SPRING O-RING O-RING EXHAUST COVER RETAINING RING DIFFERENTIAL SPRING (IF USED) CAP SCREW PRIMARY CONTROL PORT 1/4 NPT 2 3 4 5 6 1 7 8 SECONDARY CONTROL PORT CAP SCREW 1/4 NPT 9 18 DIFFERENTIAL SPRING (CONTROLS CRACK PRESSURE*) (NOT REQUIRED FOR MOST MODELS. SEE BELOW. ) 10 HORIZONTAL DELIVERY PORTS SUPPLY PORT 11 12 13 14 15 16 17 DIFFERENTIAL SPRINGS *Crack Pressure is the amount of control pressure required by the valve to initiate air delivery. For Crack pressures other than 4 psi, a differential spring is used in the assembly to produce the required valve response. (Models designed to have a 4 psi crack pressure do not require a differential spring. ) VERTICAL DELIVERY PORTS FIGURE 7 - R-12DCTM EXPLODED VIEW Caution: Drain all reservoirs before attempting to remove the inlet exhaust valve. 1. Remove the four cap screws securing the mounting bracket and cover to the body. Remove the 2 torx screws securing the double check cover (6) to the cover (1). Remove the double check cover (6) from cover (1) and remove and discard spring (2), guide (3), double check diaphragm (4), and o-ring (5). Remove and discard sealing ring (7) from the cover (1), and mounting bracket. DISASSEMBLY Note: Prior to disassembly, mark the location of the mounting bracket to the cover and the cover to the body. CAUTION: The valve body may be lightly clamped in a bench vise during disassembly, however, over-clamping will result in damage to the valve and result in leakage and/or malfunction. If a vise is to be used, position the valve so that the jaws bear on the supply ports on opposing sides of the valve's body. 4 5. Depress and hold the exhaust cover assembly (16) and remove and discard retaining ring (17) from the valve body (10). Slowly release the holding force on the exhaust cover assembly (16) to relax the spring. Install retainer (12) on inlet exhaust valve (11) and insert both in the body (10). Make certain the retaining ring is completely seated in the groove in the body. Install o-ring (5) on double check cover (6), install spring (2), guide (3) and double check diaphragm (4) in cover (1). Install the four cap screws in the cover (1) and torque to 80-100 inch pounds. Test the valve as outlined in the Operational and Leakage Test section before returning the valve to service. CLEANING AND INSPECTION 1. (Note: When servicing the R-12DCTM valve, all springs and all rubber parts should be replaced. ) 2. [. . . ] Prior to assembly, lubricate all o-rings, o-ring bores and any sliding surface with a silicone lubricant equivalent to Dow Corning #10. Using the lubricant provided in this kit, lightly lubricate all o-rings, o-ring grooves, body bores any sliding surfaces. Install sealing ring (7) on cover (1). GENERAL SAFETY GUIDELINES 5 6 ABS/TRACTION WARNING INDICATORS PARKING VALVE WHEEL SPEED SENSOR TONE RING ABS ECU SPRING BRAKES SR-1TM SPRING BRAKE VALVE SERVICE BRAKE VALVE MODULATOR ANTI-COMPOUND LINE ENGINE ECU ANTI-COMPOUNDING SPRING BRAKE RELAY VALVE MODULATOR BRAKE CHAMBER DC-4TM DOUBLE CHECK VALVE R-12DCTM RELAY VALVE AIR DRYER FRONT AXLE SERVICE RESERVOIR SUPPLY RESERVOIR SINGLE CHECK VALVE LOW PRESSURE WARNING INDICATOR GAUGE SPRING BRAKES REAR AXLE SERVICE RESERVOIR DIAGNOSTIC CONNECTION TONE RING WHEEL SPEED SENSOR MODULATOR QUICK RELEASE VALVE MODULATOR WHEEL SPEED SENSOR TONE RING COMPRESSOR FIGURE 8 - TYPICAL PIPING SCHEMATIC 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. [. . . ]