User manual BENDIX SLACK ADJUSTERS

[. . . ] Bendix Manual Slack Adjusters WORM SHAFT (LOCK SCREW) WORM GEAR LOCK SLEEVE ADJUSTING SCREW (WORM SHAFT) ADJUSTING GEAR GREASE HOLE SPLINE FIGURE 1 - POSITIVE LOCK TYPE SLACK ADJUSTER WORM GEAR ADJUSTING GEAR ADJUSTING SCREW (WORM SHAFT) SPLINE FIGURE 2 - BALL INDENT TYPE SLACK ADJUSTER DESCRIPTION In an s-cam type foundation brake, the final link between the pneumatic system and the foundation brake is the slack adjuster. The arm of the slack adjuster is fastened to the push rod of the chamber with a yoke, and the slack adjuster spline is installed on the brake cam shaft. Primarily, the slack adjuster is a lever, converting the linear force of the air chamber push rod into a torque which turns the brake cam shaft and applies the brakes. Standard slack adjusters contain four basic components; the body, worm, gear and adjusting screw. [. . . ] Apply a sufficient amount of grease to completely fill body cavity. Apply brakes and check that slack adjusters rotate freely and without binding. Release brakes and check that slack adjusters return to the released position without binding. With brakes released, check that the angle formed by the slack adjuster arm and actuator push rod is greater than 90 degrees. All slack adjusters should be set at this same angle. With brakes applied, check that the angle formed by the slack adjuster arm and actuator push rod is still slightly greater than 90 degrees. All slack adjusters should be set at this same angle. REMOVAL AND INSTALLATION CAUTION: Before attempting to remove slack adjusters, proper precautions should be taken so that an automatic application of the actuators does not occur while removing or installing slack adjusters, thus causing possible injury. Decreasing air pressure can cause a sudden full brake application without warning. Depending on type of system on vehicle, it maybe necessary to drain all air reservoirs or mechanically back off spring brake chambers. A. Remove the retaining mechanism from end of brake cam shaft. Rotate the slack adjuster by turning the adjusting nut. Slide the slack adjuster off of the spline end of the brake cam shaft. Install slack adjuster on brake cam shaft so the adjustment screw and grease fitting (if so equipped) are accessible for servicing. Install retaining mechanism on end of brake cam shaft to hold slack adjuster in place. Turn adjusting nut to line up yoke pin hole with arm hole. Refer to steps 3 and 4 under "Service Tests" and make sure the proper adjustments are made after installing a slack adjuster. SLACK ADJUSTER REPLACEMENT When replacing one type of slack adjuster with another type, it is necessary to match or exceed the torque rating and match the arm length, yoke pin diameter, offset spline diameter and width. It is also necessary to make certain that there is adequate clearance at release and full stroke. DISASSEMBLY AND ASSEMBLY NOTE: Disassembly and assembly instructions apply only to assemblies with riveted covers. Assemblies with welded covers are considered non-serviceable and are replaced as an assembly. TYPE 20 TO 30 WITH POSITIVE LOCK MECHANISM AND RIVETED COVER DISASSEMBLY 1. Before removing worm shaft, measure height from top of adjusting screw to the slack adjuster body. This measurement is important, as it serves as a reference when the worm shaft is reassembled. [. . . ] Before installing welch plug, grease bottom of shaft. Lubricate slack adjuster as outlined in "Preventive Maintenance" section. 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. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels. [. . . ]