Hoist Circuit Component Repair; Hoist Valve; Hoist Valve And Piping - Komatsu 930E-2 Shop Manual

HOIST VALVE

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. Ensure adequate overhead clearance and raise
truck body. Secure body in raised position with
safety cable.
2. Using standard procedure, shut down engine and
turn key switch to the off position. Slowly move
hoist lever to "LOWER" position to allow body to
lower against safety cable and relieve hoist cyl-
inder pressure.
FIGURE 8-1. HOIST
VALVE AND PIPING
1. Hoist Cylinders
2. Brake/Hoist Return
Oil Manifold
3. Overcenter Manifold
4. Hoist valve
5. Bleeddown Manifold
6. Pump Driveshaft
7. Hoist Circuit Filters
8. Hydraulic Tank
9. Hoist Valve Pilot
Circuit Hoses
L08024

HOIST CIRCUIT COMPONENT REPAIR

Hoist Circuit Component Repair
3. Thoroughly clean the exterior of the hoist valve.
4. Mark, disconnect and cap or plug all line connec-
tions to help prevent hydraulic oil contamination,
refer to Figure 8-1.
5. Remove capscrews and lockwashers securing
the hoist valve to its mounting bracket.
The hoist valve weighs approximately 425 lbs. (193
Kg). Use a suitable lifting device that can handle
the load safely.
6. Attach a lifting device to the hoist valve and
remove valve from truck.
7. Move the hoist valve to a clean work area for
disassembly.
L8-1