TM 10-3930-669-20 (4) Install two oil lines (2) on elbows (3 and 4) and tighten fittings (1). c.  Adjustment. NOTE Ensure forklift is on level ground. (1) Start engine (TM 10-3930-669-10). (2) Close  mast  (11)  and  position  mast  forks  3  feet (0.91 m) above ground (TM 103930-669-10). NOTE Racking is when both tilt cylinders do not reach full extension at the same time.  This causes twisting of mast. (3) Tilt  mast  (11)  backward  to  full  extent  (TM  10- 3930-669-10)  and  observe  tilt  cylinders  (9)  for racking. NOTE If mast is racking, go to Step (4) below.  Otherwise go to Step (7). (4) Loosen screw (13) on lower clevis  (14) on each tilt cylinder (9). (5) Loosen  clamp  (15)  and  pull  back  boot  (16)  on each tilt cylinder (9). (6) Adjust  each  tilt  cylinder  (9)  at  flat  (17)  until  tilt cylinders do not cause racking. 17-25