Komatsu 830E-AC Shop Manual page 790

HYDRAULIC SYSTEM FLUSHING PROCEDURE
The following instructions outline the procedure for
flushing the hydraulic system:
1. Shut down engine and turn key switch OFF.
Allow at least 90 seconds for the accumulator to
bleed down.
2. Thoroughly clean the exterior of the tank. Be
prepared to contain approximately 901 l (238
gal.) of hydraulic oil. Drain the hydraulic tank
and flush the interior of hydraulic tank with a
cleaning solvent. Inspect all hydraulic hoses for
deterioration or damage.
3. Remove, clean and replace the hydraulic tank
strainers. Change both hydraulic filter elements,
and also high pressure steering filter element.
NOTE: The final filter in the filling apparatus must be
3 micron.
4. Fill the hydraulic tank with clean, Type C-4
hydraulic oil.
5. Bleed trapped air inside steering pump. Refer to
"Pump Pressure Setting", this Section for air
bleeding procedure.
NOTE: If trapped air is not bled from steering pump,
possible pump damage and no output may result.
6. Set all controls in the "Neutral" position. Do not
steer the truck or operate controls until the next
step is completed.
7. Start the engine and run at 1000 RPM for five
minutes. This will circulate oil with all valves in
the neutral position.
8. To increase flow and turbulence in the system,
increase engine speed to full throttle and main-
tain for four minutes. This will circulate oil with
all valves in the neutral position.
9. Shut down engine and turn key switch OFF.
Allow at least 90 seconds for the accumulator to
bleed down. This will return all contaminants to
the hydraulic tank.
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10. To be able to fully extend the hoist cylinders in
the following procedure, disconnect hoist limit
solenoid in brake cabinet behind cab.
11. Restart engine and run at 1000 RPM while per-
forming the following:
a. Steer truck full left then full right - repeat four
b. Steer full left (keeping pressure against the
c. Steer full right (keeping pressure against the
12. Increase engine speed to full throttle and steer
full left and full right.
NOTE: Hydraulic tank oil temperature should be 43°-
54°C (110°-130°F) after accomplishing Step 12. If
not, repeat Step 11 to increase oil temperature to the
proper operating range.
13. Return all controls to "Neutral".
Be certain that their is enough clearance from
power lines, ceiling or any other structures that
will allow raising the body to the full up position
without hitting anything.
14. Reduce engine speed to 1000 RPM and per-
form the following:
a. Extend hoist cylinders fully and FLOAT down
b. Extend hoist cylinders and hold at full exten-
c. Lower hoist cylinders and hold lever in power
Hydraulic Check-out Procedure
times.
steering wheel) and hold for 10 seconds.
steering wheel) and hold for 10 seconds.
- repeat four times.
sion for 10 seconds. Hoist control lever must
be held in the power up position.
down position for 10 seconds after cylinders
are fully retracted.
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