User manual BENDIX MV-3 DASH CONTROL MODULE

[. . . ] This complies with Federal Regulations that one control must apply all the parking brakes on the vehicle. 7. If the MV-3TM valve fails to operate as described replace or repair it using genuine Bendix parts. Close all reservoir drain cocks and deliberately caused leakage points before placing the vehicle in service. TRAILER CHARGE (FIGURE 4) If both buttons are out when parking the combination vehicle and it is desired to recharge the trailer (leaving the tractor spring brakes applied), the red button may be pushed in, repressurizing the trailer supply line. This mode might also be used to park a combination vehicle with air actuated emergency brakes on the trailer to provide demonstrated parking capability with tractor spring brakes only. WARNING! [. . . ] must be of equivalent size, type and strength as original equipment and be designed specifically for such applications and systems. 3 AUTOMATIC APPLICATION With both buttons in (the normal run configuration), if the supply pressure to the push-pull valves is reduced to approximately 20 to 45 P. S. I. , the red button (trailer supply valve) must pop out, applying the emergency or parking brakes on the trailer. If the red button is held in manually and the pressure decreases to approximately 20 P. S. I. , a tripper piston within the MV-3TM valve will move upward, exhausting the trailer supply, effecting the required nonoverride feature. OPERATIONAL TEST 1. Hold the red button in and continue to reduce pressure in all service reservoirs. Air must start to escape from the exhaust port when the trailer supply line pressure reaches 20 P. S. I. Release the red button and rebuild the supply pressure to at least 120 P. S. I. Components with stripped threads or damaged parts should be replaced rather than repaired. Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition. CAUTION: Note the orientation of the buttons in relation to the valve to be sure they will be replaced properly. DISASSEMBLY OF THE MV-3TM VALVE 1. Remove the red (1) and yellow (2) buttons from the stems of the spools on the MV-3TM valve by turning in a counterclockwise direction. Remove and save the mounting hardware from the four corners of the cover plate (3). If removing the valve from the vehicle, remove and identify the air lines from the back of the valve. 1 2 4. Remove the six Phillips head screws (4) from the cover plate (3) and carefully remove the cover plate (3) from the valve. 4 5. These parts will all fall out of the cavity of the MV-3TM valve by tilting the body forward. Remove the two main spools from the body of the MV-3TM valve by grasping the stem and pulling firmly. Pull the guide spool (14) over the threaded end of one of the plungers (15). Remove o-rings (18, 19 & 20) and the exhaust seal (21) from the plunger. Remove the retaining ring (22) from the cavity of the MV-3TM valve body that contains the dual circuit supply valve. Remove the check valve (17) from the MV-3TM valve body. 16 3 14 16 18 19 5 15 6 7 11 21 20 12 8 9 10 21 20 12 15 19 14 18 CLEANING & INSPECTION The non-metallic components which comprise most of the parts of the MV-3TM valve should not be immersed in any solvent type cleaner. [. . . ] Install the cover plate (3) onto the valve body and retain with the six Phillips head screws. Attach the red (1) and yellow (2) buttons onto the threaded stems of the spools, making sure that they are oriented correctly as noted in Step 1 of Disassembly procedure. Reattach the MV-3TM valve to the dash using the hardware removed in Step 2 of Disassembly. If air lines were removed during disassembly, reconnect to ports marked during disassembly. [. . . ]