User manual BENDIX SLACK ADJUSTERS

[. . . ] The worm meshes with and rotates the slack adjuster worm gear which is connected to the brake cam by a splined cam shaft. The turning of the slack adjuster worm gear rotates the cam shaft and brake cam, spreading the brake shoes, compensating for brake lining wear. There are two types of adjusting mechanisms used on Bendix slack adjusters currently manufactured. 1) use a positive lock mechanism consisting of a spring loaded lock sleeve, which when positioned properly, engages the adjusting screw nut, preventing the adjusting screw (worm shaft) from rotating. [. . . ] COMPRESSION MOUNTING IS RECOMMENDED AND WILL YIELD A LONGER SERVICE LIFE. NOTE: Some Bendix slack adjusters were manufactured without a lubrication provision in the body; however, the slack adjuster may be lubricated through the cover as follows: 1. Determine which side of slack adjuster is accessible for lubrication and install washer (Pc. 244017) Alemite #1625 using Alemite tool #5254 to press grease fitting firmly in place in cover. 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. With brakes applied, check that the angle formed by the slack adjuster arm and actuator push rod is still slightly greater than 90 degrees. 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. 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. 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. Press out worm shaft from worm by pressing in on the end of the worm shaft opposite the adjusting screw nut. Before removing worm shaft, measure height from top of adjusting screw to the slack adjusted body. This measurement is important, as it serves as a reference when the worm shaft is reassembled. [. . . ] Following the vehicle manufacturer's recommended procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted. must be of equivalent size, type and strength as original equipment and be designed specifically for such applications and systems. TEST OF REBUILT SLACK ADJUSTERS After lubricating rebuilt slack adjuster (see "Preventive Maintenance" section), all moving parts of the slack adjusters should rotate freely and not bind. [. . . ]