Komatsu 930E-2, Shop Manual

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The following procedures involve raising and low-
ering the dump body. Be certain adequate clear-
ance is available before raising body to the full
“up” position.
10. Reduce engine speed to 1000 RPM and perform
the following:
In all of the following “UP” exercises, as the sec-
ond stage starts out of the hoist cylinder in the
POWER UP mode, slowly decrease engine speed
to prevent sudden bottoming of the cylinders. Se-
vere damage to the hoist cylinders may occur if
this precaution is not followed.
a. Extend hoist cylinders fully and “FLOAT” down
- repeat ten (10) times.
b. Extend hoist cylinders to full extension and
hold hoist lever in “UP” position for 10 sec-
onds.
c. Lower hoist cylinders and hold lever in
“DOWN” position for 10 seconds after cylin-
ders are fully retracted.
11. Increase engine speed to full throttle and perform
the following:
a. Hoist up to full extension, then allow cylinders
to float down.
b. Return hoist control to “Float”.
12. Operate the truck (on a typical haul cycle if
possible) to exercise the braking functions a mini-
mum of 30 times. Insure the braking is also exer-
cised in “Reverse”, as would be seen in a typical
haul cycle.
13. If the truck is equipped with any hydraulically
operated attachment, the attachment must also
be cycled in a similar manner, following the
checkout procedure or Operational Instructions
for the device.
14. Shut down engine and turn key switch OFF.
15. Allow at least 90 seconds for the accumulators to
bleed down. Turn the steering wheel to be certain
all pressure has been released.
16. Reconnect hoist limit solenoid on bleeddown
manifold.
Filter Element Replacement
After the hydraulic system flushing procedure has
been completed, all system high pressure filter ele-
ments must be replaced.
1. Close both hoist pump suction line shut-off
valves. Close the steering pump suction line
shut-off valve.
2. Remove hoist, steering, and brake circuit hydrau-
lic filters, clean housings and install new filter
elements. (Detailed instructions may be found in
Section L9.)
3. Check hydraulic tank oil level and refill if neces-
sary.
4. Open all (three) suction line shut-off valves.
L10012 Hydraulic Check-out Procedure L10-11