TM10-3930-660-20 18-32. BOOM  HOIST  CYLINDERS   - REPLACE (Cont'd) 1. 2. 3. Be START ENGINE, TM10-3930-660-10. WISE BOOM SO BOOM HOIST CYLINDER UPPER PIVOT PINS (1) ARE ABOVE CAB. STOP ENGINE, TM10-3930-660-10. WARNING sure boom is supported with lifting device before upper-pivot pins (1) are removed. Failure to support boom during removal of upper pivot pins (1) could result in personal injury or death. Combined weight of boom and MLRS attachment is 6300 lbs. Weight of boom alone is approximately 4100 lbs. 4. SUPPORT BOOM WITH LIFTING DEVICE. 5. REMOVE BOOM HOIST CYLINDER PIVOT  PIN  (1). a. b. c. d. Place wood board behind vehicle deck to support (2) when it is lowered. UPPER cab on cylinder Place wood block under rod eye of cylinder (2) to prevent accidental damage to cylinder rod eye during removal. Support cylinder (2) to be removed using a suitable lifting device. Remove locknut (3), screw (4) and pivot pin (1), using suitable pin puller. Discard locknut (3). If removing one cylinder (2), have assistant signal operator when cylinder (2)  is  fully  retracted. 18-128