TM10-3930-660-34 16-9.  FRAME TILT CYLINDER - REPAIR (Cont’d NOTE Note and mark location of counterbalance valves  (1)  for  use  during  assembly.    The valves (1) are not interchangeable. 2. RELIEVE   PRESSURE   IN   CYLINDER   BY   SLOWLY REMOVING     TWO     COUNTERBALANCE     VALVES (1).DRAIN RESIDUAL OIL THROUGH VALVE HOLES INTO A SUITABLE  CONTAINER. 3. REMOVE  BACK-UP  RINGS  (2  AND  3),  TWO  BACK- UP  RINGS  (4),  AND  THREE  O-RINGS  (5-7)  FROM EACH  COUNTERBALANCE  VALVE  (1).DISCARD  O- RINGS (5-7). 4. DISASSEMBLE CYLINDER PARTS (8-19). CAUTION Do  not  scratch  or  damage  the  wear  surface  of  rod  (8), piston (15) or gland (9).Follow this precaution to prevent failure of the cylinder. a. Use     a     suitable tool to pull rod (8) out approximately 5 inches for removal of gland (9). b. Place  a  container  under  gland  (9)  to  catch  oil contained in cylinder. c. Use a spanner wrench to remove gland (9) from cylinder tube (10).  Pull gland (9) out of cylinder far  enough  to  unseat  O-ring  (11).    Allow  oil  to drain into container. CAUTION Use   care   when   removing   rod   (8)   and piston   assembly   to   prevent   wear   ring (12)  damage.  Keep  rod  (8)  in  line  with cylinder tube to prevent binding. d. Remove    rod    (8)    and    piston    assembly    from cylinder tube (10). 16-38