Remove nut (6) and lockwasher (7).
Pulling from the base (8) end, remove the cylinder (9) from the guide (10).
Remove snap ring (11) and withdraw rod and piston (12) and bearing (13). Slide the bearing (13) off the rod
Remove o-ring (14), wiper (15) and seal (16) from bearing (13), and remove seals (17) and ring (18) from piston
(12). Discard rings and seals.
Examine bushing (19) to see if there is wear or damage. If replacement is required, remove snap ring (20) and
pull bushing (19) from guide (10).
Examine all parts and replace parts as required. Use new seals at assembly.
If new bushing (19) is being used, position the bushing squarely in the bore of the guide (10) and push the
bushing in evenly. The old bushing may be used as a drift to push the new bushing in. Install snap ring (20).
Install seals (17) and ring (18) in the grooves of the piston (12).
Lightly coat the piston and seals with clean hydraulic fluid and insert the rod and piston (12) into the cylinder (9).
Install o-ring (14), wiper (15) and seal (16) in bearing (13).
Lightly coat the inside and outside diameters of the bearing (13) and slide it over the end of the rod (12) and into
the cylinder (9). Use care that the o-ring (14) is not damaged on the snap ring groove in the cylinder.
Push bearing (13) in far enough to pass the snap ring groove, and install snap ring (11) in cylinder (9).
Install assembled cylinder (9) in guide (10).
Rotate rod (12) so that the threaded hole in rod is aligned with the opening guide. Install nipple (5).
Install the lockwasher (7) and nut (6). Screw the elbow (2) and nipple (3) into rod (12).
Install check valve (4) and connect hose (1).
4-13 MAINTENANCE OF THE MAST
4-13.1 Crown Block Assembly. (Figure 4-33)
4-13.1.1 Hoisting and Auxiliary Sheaves.
Remove grease fitting (1), screws (2), lockwashers (3) and lockplate (4).