Hydraulic System Flushing Procedure - Komatsu 830E Shop Manual

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 238 gal. (901
l) of hydraulic oil. Drain the hydraulic tank and
flush the interior of hydraulic tank with a clean-
ing solvent. Inspect all hydraulic hoses for dete-
rioration 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.
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
times.
b. Steer full left (keeping pressure against the
steering wheel) and hold for 10 seconds.
c. Steer full right (keeping pressure against the
steering wheel) and hold for 10 seconds.
L10-18
12. Increase engine speed to full throttle and steer
full left and full right.
NOTE: Hydraulic tank oil temperature should be
110° -130° F (43°- 54° C) 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 perform
the following:
a. Extend hoist cylinders fully and "FLOAT"
b. Extend hoist cylinders and hold at full exten-
c. Lower hoist cylinders and hold lever in power
15. Increase engine speed to full throttle and per-
form the following:
a. Hoist up to full extension, hold for 10 sec-
16. Return hoist control to "Neutral".
17. Shut down engine and turn key switch "Off".
Allow at least 90 seconds for the accumulator to
bleed down.
18. Reconnect hoist limit solenoid in brake cabinet.
19. Close both hoist pump suction line shut-off
valves. Close steering pump suction line shut-
off valve.
20. Remove hoist & steering filter elements. Clean
housings and install new elements.
21. Fill hydraulic tank if necessary.
22. Open all (three) suction line shut-off valves.
Bleed all air from pump suction lines and steer-
ing pump before starting engine. Refer to
"Pump Pressure Setting", Section "L" for air
bleeding procedure.
Hydraulic Check-out Procedure
down - 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.
onds, then allow cylinders to float down.
05/03 L10016