4-55. POWER CLUSTER AND MASTER CYLINDER - REPLACE.
This Task Covers:
Tool Kit, General Mechanic's: Automotive (Appendix B, Section III, Item 1).
Brake fluid (Appendix E, Section II, Item 2).
Teflon Tape (Appendix E, Section II, Item 7).
Rags, wiping (Appendix E, Section II, Item 1).
Dry cleaning solvent (Appendix E, Section II, Item 3).
Nut, self-locking (Appendix H, Section II, Item 10).
Lockwasher (Appendix H, Section II, Item 7).
Unit shut down and cool.
a. Removal. (Refer to Figure 4-55).
Compressed air may cause severe injury or death, if not used properly.
Make sure that air pressure in trailer brake system is completely drained
Completely vent trailer air brake system pressure by opening drain valve. (para. 4-51).
Disconnect air brake line (1) from elbow (2). Remove elbow (2) from power cluster (3).
Remove two nuts (4) and two lockwashers (5) from back side of bracket (6). Discard two lockwashers.
Remove power cluster (3) and spacer (7) from bracket (6).
Loosen brake line (8) from adapter (9) allowing brake fluid to drain into cup or other suitable container. Plug
brake line (8) after draining.
Remove three screws (10), and three self-locking nuts (11) holding master cylinder (12) to bracket (6). Discard
three self-locking nuts.
Slide master cylinder (12) out of bracket (6).
Loosen hose clamp (13) on rubber hose (14), and remove from hydraulic brake vent tubing (15).
Unscrew adapter (16) from cap (17) and remove vent tube (15) and adapter (16). Inspect packing (18) on cap
(17) and remove if damaged.