User manual BENDIX BP-1 BRAKE PROPORTIONING VALVES

[. . . ] ® Bendix® BP-1TM Brake Proportioning Valves 1. 5 . 340" MOUNTING HOLES (2) 3/8 P. T. TAG STAMPED BP-1 FRONT OR BP-1 REAR 3/8 P. T. DELIVERY PORT FIGURE 1 BP-1TM BRAKE PROPORTIONING VALVES DESCRIPTION OF THE BP-1TM VALVES The BP-1TM brake proportioning valves are incorporated into the air brake systems to improve the controllability and reduce the stopping distance of bobtail tractors during braking. BP-1TM, front and rear, valves reacting to the lack of pressure in the trailer supply line reduce the braking effort on the rear axles and increase the braking effort on the front axle of tractors operating in the bobtail mode. [. . . ] 1 1 1 Description BP-1TM (Rear) Valve TR-3TM Inversion Valve BP-1TM (Front) Valve REPLACES FRONT AXLE LIMITING VALVE TEE FITTING EXISTING LINE Ë Ê TEE FITTING Ì BRAKE VALVE EXISTING REAR AXLE SERVICE DELIVERY LINE REAR AXLE SERVICE RELAY VALVE EXISTING FRONT AXLE SERVICE DELIVERY LINE TEE FITTING REAR AXLE SERVICE RESERVOIR FIGURE 6 TYPICAL INSTALLATION SCHEMATIC OF BRAKE PROPORTIONING SYSTEM 9. 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. 4. Install the BP-1TM rear valve into the service line from the brake valve. Connect the delivery line from the brake valve to the supply port of the BP-1TM valve and the delivery port of the BP-1TM valve to the control port on the relay valve. Connect the TR-3TM inversion valve as follows. Tee the control port to the delivery of the trailer supply valve, the supply port to the supply line of the brake valve, and connect the delivery port to the control port of the BP-1TM valve. Note: If vehicle does not have a front axle ratio or limiting valve, proceed to "Operational Checks". If vehicle has a front axle ratio or limiting valve, continue with Step 6. Remove the existing front axle ratio or limiting valve and replace it with the BP-1TM front valve. Connect the front axle brake valve delivery line to the supply port of the BP-1TM valve, the delivery port of the BP-1TM valve to the front axle actuators, and the control port of the BP-1TM valve to the delivery of the TR-3TM inversion valve. INSTALLATION (REFER TO FIGURE 6) 1. The vehicle being fitted with a BP-1 TM rear brake proportioning valve must be equipped with a rear axle service relay valve. It cannot be installed on a vehicle utilizing a quick release valve system without a relay valve. For vehicles equipped with a front axle service ratio or limiting valve (such as the Bendix® LQ-4TM valve) it must be removed and replaced by the BP-1TM front valve provided in kit #209924. Caution: The front and rear BP-1 TM valves are not interchangeable. They are identified with a metal tag stamped `BP-1 Front' or `BP-1 Rear' attached to one of the cap screws on the cover. Mount the BP-1TM rear valve and the TR-3TM inversion valve in a protected area that is convenient to the service line between the brake valve and the relay valve. OPERATIONAL CHECKS After components have been installed and all connections made, perform the following checks. With the trailer supply valve pulled out (bobtail running position) install two air gauges in the service system; one at an actuator on the front axle and one at an actuator on a rear axle. 4 2. Build system pressure to governor cut-out setting. Make a service brake application with the foot valve and have another person or persons observe the gauges. When the front axle gauge reaches a 40 psi application the rear axle gauge should read approximately 10-20 psi depending on rear axle relay valve differential. [. . . ] Use needle nose pliers to install spring(6) by grasping spring on the bar that intersects the end of the spring and twisting in a clockwise motion while pressing down. Caution: Be sure inlet/exhaust valve is seated flat against the bottom of the piston and the spring is fully seated below the step on the I. D. Install the lower piston assembly into the body of the valve. Install the piston spring into the body of the valve. [. . . ]