PUMP G 7N4864 - Caterpillar

Make certain that oil is circulating through the brake before the winch is operated under loaded conditions. Check for oil flow at the cooling oil circulation return ports of the winch.
Disassemble Boom Winch
Start By:a. remove boom winch 1. Drain the oil from the winch by removing plug (58). Tip the winch on an angle to drain all the oil.
The boom winch drive motor adapter (82) compresses springs (37) when fastened to brake housing (22). To prevent injury from flying parts while removing winch drive motor (87), loosen bolts (85) one turn at a time until the springs (37) are relaxed.
2. Fasten a hoist to the winch drive motor (87). Remove twelve bolts (85) and washers (86). Remove winch drive motor (87). See this manual for D&A.3. Remove sixteen springs (37).4. Remove shaft (33). Brake hub components (27), (29), (30), (31), (88) and (32) will come out with shaft (33).5. Remove thrust bearing (21) and two thrust washers (20).6. Remove retaining ring (34) and retaining ring (28) from shaft (33).7. Remove retaining ring (32) from shaft (33). Slide brake hub (29), two washers (27), two plates (30), (88) and two sprag clutches (31) from shaft (33).8. Remove plates (30), (88) and sprag clutches (31) from brake hub (29).9. Inspect O.D. of shaft (33) and I.D. of brake hub (29) where sprag clutches (31) contact them. If indentations or surface damage is present, the damaged part should be replaced.10. Remove brake piston (35) from brake housing (22).11. Remove O-ring seals (36) and (38) from brake piston (35).12. Inspect brake piston (35) O.D.'s and brake housing (22) I.D.'s for surface defects. Polish O.D. with fine emery cloth if defects are evident.13. Remove six friction discs (26) and seven divider plates (25) from brake housing (22).14. Remove spacer plate (24) from brake housing (22).15. Remove twelve bolts (51) and washers (53). Remove winch base (52) from brake housing (22) and