User manual BENDIX ATR-2 ANTILOCK TRACTION VALVE

[. . . ] ® Bendix® ATR-2TM AntiLock Traction Relay Valve CONTROLLER OR COVER PLATE MOUNTING HOLES: SEE NOTE BOBTAIL PROPORTIONING VALVING TRACTION CONTROL SOLENOID MOUNTING BRACKET SERVICE PORT COVER CONTROL PORT BODY SUPPLY PORT DELIVERY PORT (4) NOTE: AN OPTIONAL COVER PLATE IS INSTALLED OVER THE TOP WHEN THE ATR-2TM VALVE IS MOUNTED REMOTE FROM THE ANTILOCK TRACTION CONTROLLER FIGURE 1 - ATR-2TM ANTILOCK TRACTION RELAY VALVE 2 PIN SOLENOID CONNECTOR SUPPLY PORT DESCRIPTION The ATR-2TM antilock traction relay valve is a specialized air brake valve developed for use on Bendix antilock/traction equipped tractors only. It is essentially three separate valves working in combination in a single housing. An R-14TM style service relay valve is the base valve and is fitted with a modified cover containing a bobtail tractor brake proportioning valve (reference Bendix Service Data Sheet SD-03-1067) and a traction control solenoid. The ATR-2TM valve contains both air and electric components and provides both the service braking and traction control (differential braking) functions. [. . . ] Note that when service port pressure rises to between 20 and 30 psi, delivery pressure begins to rise above the initial pressure noted in step 6. The rise of delivery pressure should be at a proportioned rate of approximately 3 to 1. At 70 psi service pressure, delivered pressure should be 15 to 25 psi. Make a full brake application and note that both test gauges register the same pressure. IMPORTANT: If during testing, the service port pressure is SLOWLY increased from approximately 70 psi to a full (100 psi or greater) brake application, the ATR-2TM valve MAY begin to cycle between an apply and exhaust mode. This condition is normal while the ATR-2TM valve is transitioning from the proportioning mode to the full delivery mode and will only occur if the service application is SLOWLY increased as described. Cycling will not occur or can be stopped by increasing or decreasing service port pressure. Disconnect the ATR-2TM valve's two pin solenoid connector from the wire harness. Apply the probes of a volt-ohm meter to the connector leading to the solenoid and note the resistance of the solenoid is between 10 and 12 ohms. Apply and remove vehicle power (12 vdc) to the two pin connector half leading to the ATR-2TM valve (solenoid) while observing the brake chamber gauges. Note that a full brake application is made and held while power is applied to the ATR-2TM valve's solenoid and that it is released when power is removed. Remove the test gauges from the ATR-2TM valve. LEAKAGE TESTS 1. Build the air system pressure to governor cut-out. With the dash mounted trailer supply valve activated for tractor/ trailer operation, apply a soap solution to all three exhaust ports (two in cover and one in body). The leakage noted should not exceed a 1" bubble in less than 3 seconds at any exhaust port. Make and hold a full brake application and apply a soap solution to all three exhaust ports and around the cover where it joins the body. The leakage noted should not exceed a 1" bubble in less than 3 seconds at any exhaust port. If the ATR-2TM valve fails to function as described, or leakage is excessive, it should be replaced with a new or genuine Bendix remanufactured unit or repair using maintenance kit piece number 109359, available at any Bendix authorized parts outlet. VEHICLE PREPARATION 1. Park the vehicle on a level surface and block the wheels and/or hold the vehicle by means other than the air brakes. Drain the air pressure from all vehicle reservoirs. REMOVAL 1. Identify and mark or label all electrical wiring harnesses and air lines and their respective connections on the assembly to facilitate ease of installation. Disconnect the air lines and wire harnesses. [. . . ] Make certain the retaining ring is fully seated in its groove. Make sure the valve is straight, against the exhaust seat and free to move. Install both the large and small diameter o-rings(27 & 29) on the proportioning piston(28). Install both the large and small diameter o-rings(25 & 26) on the blend back piston(24), then insert the small diameter of the proportioning piston(28) into the small diameter end of the blend back piston(24). [. . . ]