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motor, with the exception of the motor adaptor, item 800, and the port end cover, item 870, are standard parts of
the hydraulic motor, having a 3 inch gear section. All of these parts can be ordered from PULLMASTER or
Authorized Distributors/Dealers in Canada, the United States and in most overseas areas.
REMOVAL OF HYDRAULIC MOTOR ASSEMBLY:
If disassembly of the hydraulic motor is not necessary, proceed as follows:
1)
Remove the 12 hex head capscrews, item 537, with lockwashers, item 541, from the motor adaptor, item 800.
Since the brake springs, item 752, apply pressure against the inside of the motor adaptor, it is recommended
that the hex capscrews are unscrewed, one turn at a time, until the spring pressure has been released. The
complete motor assembly, including the motor adaptor, can now be removed from the brake housing assembly.
2) Remove and discard three O-rings, item 801, and O-ring, item 707. (O-rings, item 801, seal the pressure
transfer hole for the automatic brake release and are situated on the flange of the brake housing.)
DISASSEMBLY OF BRAKE HOUSING ASSEMBLY:
1) After the motor assembly has been removed, all parts of the brake assembly are accessible. Remove 18
brake springs, item 752. Thoroughly examine springs for damage and measure overall length. Overall spring
length should be 2.27 inch. If any spring measures less than 2.21 inch, replace all springs as a set.
2) Pull the motor drive shaft, item 730, out of the brake hub assembly. The surface of the motor drive shaft which
engages the sprag clutch, item 723, should be inspected for wear or indentations. If the motor drive shaft
shows any surface damage, it should be replaced.
3) The sprag clutch aligner, item 724, and the sprag clutch, item 723, can now be removed from the bore of the
brake connecting shaft, item 600. Inspect both parts for wear or damage and replace if necessary.
DANGER
MINOR SURFACE DEFECTS WHERE THE SPRAG CLUTCH ENGAGES THE
MOTOR DRIVE SHAFT AND CONNECTING SHAFT, WILL RESULT IN BRAKE
FAILURE AND ALLOW THE LOAD TO DROP, CAUSING PROPERTY
DAMAGE, SEVERE INJURY OR DEATH. THOROUGHLY INSPECT
THESE AREAS AND, IF NECESSARY, REPLACE MOTOR DRIVE
SHAFT, SPRAG CLUTCH AND CONNECTING SHAFT AS A SET.
4) Pull the brake piston, item 750, out of the brake housing using two 5/8-11NC bolts screwed into the two puller
holes in the piston and discard O-rings, item 751 and item 753.
5) Thoroughly examine the inner bores of the brake housing and the outer diameters of the brake piston for
scoring caused by hydraulic fluid contamination. Minor surface damage may be repaired by polishing with
a fine emery cloth.
DAMAGED FRICTION OR DIVIDER PLATES WILL REDUCE BRAKING
CAPACITY AND ALLOW THE LOAD TO DROP, CAUSING PROPERTY
DAMAGE, SEVERE INJURY OR DEATH. SOLVENT MAY DAMAGE THE
FRICTION PLATES. DO NOT USE SOLVENT TO CLEAN THE FRICTION
PLATES. PERFORM THOROUGH INSPECTION AND, IF NECESSARY,
REPLACE FRICTION AND DIVIDER PLATES AS A SET.
6) Remove 12 friction plates, item 715, together with 13 divider plates, item 713, and inspect for damage or wear.
Plates should be flat and smooth. Plates should not show heat discoloration. Paper material on friction plates
251 REV.021126
SERVICE INSTRUCTIONS CONTINUED
DANGER
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