Service Manual

Workman HD SeriesPage 9 -- 56Hydraulic System
Lift Cylinder Service
1. Lock nut
2. Wear ring
3. Seal
4. O--ring
5. Piston
6. Head
7. O--ring
8. Back--up seal
9. Retaining ring
10. Seal
11. Wiper
12. Barrel
13. Shaft
14. O--ring
Figure 44
1
2
3
4
5
13
14
6
7
8
9
10
11
12
60 to 75 ft--lb
(81 to 102 N--m)
Disassembly (Fig. 44)
1. Pump oil out of cylinder into a drain pan by slowly
moving piston back and forth.
2. Before disassembling cylinder, plug ports, wash ex-
terior with cleaning solvent and dry thoroughly.
IMPORTANT: Prevent damage when clamping the
cylinder’s barrel into a vise; clamp on the clevis
only. Do not close vise on barrel.
3. Mount lift cylinder in a vise equipped with softjaws by
clamping on the barrel clevis.
4. Remove retaining ring that secures head in barrel.
A. Use a spanner wrench to rotate head clockwise
until the edge of the retaining ring appears in the bar-
rel opening.
B. Insert a screwdriver under the beveled edge of
the retaining ring to start the retaining ring through
the opening.
C. Rotate the head counter--clockwise to remove re-
taining ring from barrel and head.
5. Extract shaft with head and piston by carefully twist-
ing and pulling on the shaft.
IMPORTANT: When securing shaft in vise, clamp on
shaft clevis only. Do not clamp vise jaws against the
shaft surface.
6. Mount shaftsecurely in a viseby clamping onthe cle-
vis of the shaft. Remove lock nut and piston from the
shaft. Slide head from the shaft.
7. Remove piston seal, O--rings and wear ring from the
piston. Remove O --ring, back--up seal, seal and wiper
from the head.
Inspection
1. Wash parts in clean solvent. Dry parts with com-
pressed air. Do not wipe parts dry w ith paper towels or
cloth. Lint in the hydraulic system will cause damage.
2. Carefully inspect internal surface of barrel for dam-
age (deep scratches, out--of--round, etc.).
3. Inspect shaft and piston for evidence of excessive
scoring, pitting or wear.
4. Replace lift cylinder if internal components are found
to be worn or damaged.