Komatsu 830E-AC Shop Manual page 763

Assembly of Cylinder
1. Install seals (15, Figure 8-18) and bearing (14)
on second stage cylinder. Install bearings (19)
and buffer seal (18), rod seal (20) and rod wiper
(21) on first stage cylinder. Lubricate with clean
hydraulic oil (Type C-4).
2. Align and slide the second stage cylinder (2)
inside the first stage cylinder (3). Allow the sec-
ond stage to protrude far enough to install the
snap ring (9) on the inside of the first stage cyl-
inder.
3. Mount the housing (4) in the fixture with the
cover end positioned at the top. Install bearings
(19) and buffer seal (18), rod seal (20) and rod
wiper (21) in the housing.
4. Install lifting tool used during disassembly in the
second and first stage cylinder assembly.
5. Install bearings (13) on the first stage cylinder
(3). Lift and align this assembly over the hous-
ing (4). Lower the second and first stage cylin-
ders into the housing.
6. Install retainer used during disassembly to hold
the second and first stage cylinder in place
when the housing is rotated. Rotate housing
180° to position the lower mounting eye at the
top.
7. Install bearings (19) and buffer seal (18), rod
seal (20) and rod wiper (21) in the second stage
cylinder (2).
8. Attach a lifting device to the rod eye (1) and
align it over the housing (4). If equipped, install
cushion ring (24) on rod. Lubricate the rod with
hydraulic oil and lower the rod into the housing.
NOTE: A cushion ring (24) can be added to hoist
cylinders even if one was not removed during
disassembly.
9. Rotate housing 180° to position the cover end
at the top. Remove retainer installed in Step 6.
Install bearings (17) and seal (16) on the rod
bearing retainer (6).
L08038
10. Thread two guide bolts 100 mm (4 in.) long in
the end of the rod (1). Install seal (8) on the end
of the rod.
11. Align piston rod bearing retainer (6) over guide
bolts and lower it over the end of the rod (1).
Remove guide bolts.
NOTE: Check cap screws carefully for distress and, if
in doubt, replace them with new.
12. Make certain threads on cap screws (1, Figure
8-22) and threads in rod are clean and dry (free
of oil and solvent).
Hoist Circuit Component Repair
FIGURE 8-22. 3rd. Stage Piston
1. 12 Pt. Cap Screw 3. Piston
2. Plate
L8-21