TM10-3930-660-34 16-12.BOOK ASSEMBLY - REPLACE (Cont’d) d. Remove capscrew (14) and locknut (15) securing  pivot  pin  (13)  to   boom   hoist   cylinder (12).Discard locknut (15). e. Support boom hoist cylinder (12).  Remove pivot pin (13) from boom assembly (8) and boom hoist cylinder (12). NOTE In    step    4f,    release    hydraulic    joystick immediately   after   boom   hoist   cylinder (12) to be removed has fully retracted.  If joystick  is  allowed  to  remain  open,  the other cylinder will start to retract, putting extreme  stress  on  lifting  equipment  and boom assembly (8). f. Start engine and run at full throttle.  Fully retract boom hoist cylinder using joystick.  Cylinder (12) will retract very slowly.  Stop engine. g. Carefully  lower  cylinder  (12)  onto  board  placed across vehicle deck so hydraulic line on cylinder is not damaged. h. Repeat  steps  4d  through  4g  for  other  cylinder (6). 5. PLACE   JACKSTAND   OR   SUPPORT   ON   FRONT OF  VEHICLE  DECK.ADJUST  SUPPORT  SO  THAT BOOM   ASSEMBLY   (8)   WILL   BE   LEVEL   WHEN LOWERED. 6. CAREFULLY LOWER BOOM ASSEMBLY (8) WITH HOIST   AND   SLING   UNTIL   FRONT   OF   OUTER BOOM  SECTION  IS  ON  JACKSTAND  OR  OTHER SUITABLE SUPPORT. 16-51