Hoist Cylinders - Komatsu 930E-2 Shop Manual

HOIST CYLINDERS

Removal
Relieve pressure before disconnecting hydraulic
lines. Tighten all connections securely before ap-
plying pressure.
Hydraulic fluid escaping under pressure can have
sufficient force to enter a person's body by pene-
trating the skin and cause serious injury and pos-
sibly death if proper medical treatment by a
physician familiar with this type of injury is not
received immediately.
1. Insure engine and key switch have been "Off" for
at least 90 seconds to allow accumulator to bleed
down. Be certain the park brake is applied.
2. Disconnect the lubrication lines to the upper and
lower bearings of the hoist cylinder.
3. Remove capscrew and lockwashers from clamps
securing the hydraulic hoses to the hoist cylin-
der. Cap and plug lines and ports to prevent
excessive spillage and contamination. Secure
cylinder to frame to prevent movement.
The hoist cylinder weighs approximately 2500 lbs.
(1135 kg). Some means of support is necessary to
prevent it from falling or causing injury when re-
moving from the truck. Use a suitable lifting device
that can handle the load safely.
L8-12
4. At the upper mount, remove self-locking nut (4,
Figure 8-18) from pin retaining capscrew. Re-
move capscrew (5). Use a brass drift and ham-
mer to drive pin (1) from bore of mounting
bracket.
5. Carefully lower cylinder until it lays against the
inside dual tire. The hoist cylinder weighs ap-
proximately 2500 lbs. (1135 kgs). Attach a suit-
able lifting device that can handle the load safely
to the upper cylinder mounting eye.
6. Install a retaining strap or chain to prevent the
cylinder from extending during handling.
7. At the lower mount, straighten lock plate tabs to
allow capscrew removal. Remove all capscrews
(1, Figure 8-19), locking plate (2) and retainer
plate (3).
8. Carefully remove cylinder from frame pivot by
pulling outward. Move cylinder to a clean area for
disassembly.
NOTE: Do not lose spacer (6, Figure 8-19) between
cylinder bearing and frame.
9. Clean exterior of the cylinder thoroughly.
FIGURE 8-18. HOIST CYLINDER UPPER MOUNT
Hoist Circuit Component Repair
1. Pin 4. Locknut
2. Retainer Ring 5. Capscrew
3. Bearing
L08024