TM10-3930-660-34 16-16.  BOOM EXTEND CYLIDER - REPLAC/REPAIR (Cont’d) a. Remove backup rings (29 and 30), two backup rings (31), and three O-rings (32- 34) from each counterbalance valve (27). Discard O-rings (32-34). b. Remove three backup rings (35-37) and three O-rings (38-40) from counterbalance valve (28).  Discard O-rings (38-40). 3. DISASSEMBLE CYLINDER PARTS (41-55). a. Remove needle valve (41). CAUTION Do not scratch or damage the wear surface of rod (42), piston or gland (43). b. Pull rod (42) out approximately 5 inches for removal of gland (43). c. Place a container under gland (43) to catch oil contained in cylinder. d. Use a spanner wrench to remove gland (43) from barrel (44).  Pull gland (43) out of cylinder far enough to unseat O-ring (45). Allow oil to drain into container. CAUTION Use care when removing rod (42) and piston assembly to prevent wear ring (46) damage.  Keep rod (42) in line with cylinder tube to prevent binding. 16-101