Komatsu 830E, Shop Manual

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L10-4 Hydraulic Check-out Procedure 05/03 L10016
LEAKAGE TESTS
Relieve pressure before disconnecting hydraulic
lines. Tighten all connections securely before
applying pressure. Hydraulic fluid escaping
under pressure can have sufficient force to enter
a person's body by penetrating the skin and
cause serious injury and possibly death if proper
medical treatment by a physician familiar with
this type of injury is not received immediately.
NOTE: The hydraulic system must be at normal
operating temperature (110°F or 43°C) or higher
before performing leakage tests.
Steering Control Unit & Flow Amplifier
1. Shut down engine and turn keyswitch “Off”. Wait
90 seconds for steering accumulator to bleed
down. Turn steering wheel to be sure no pres-
sure remains.
2. To check combined leakage from the steering
unit and the flow amplifier, disconnect flow
amplifier return hose from bleed down manifold.
Cap fitting on manifold and start engine. Maxi-
mum allowable combined leakage is 60 in.
3
(984 ml.) per minute from steering return hose.
If leakage is excessive, perform next two steps.
a. Remove steering control unit tank (return)
line at the flow amplifier (“T” port). For loca-
tion of the tank line (“T” port), refer to Figure
10-2. Plug the tank port opening on flow
amplifier.
b. Remove the flow amplifier return hose at the
“HT” port on the flow amplifier. Refer to Fig-
ure 10-2. Plug the return hose.
c. Start engine and run at low idle.
d. Measure leakage from steering control unit
tank line. Leakage not to exceed 10 in.
3
(164
ml) per minute. If leakage is excessive,
replace steering control unit.
e. Measure leakage from the flow amplifier at
the “HT” port. Maximum allowable leakage is
50 in.
3
(820 ml) per minute. If leakage is
excessive, replace flow amplifier.
f. Shut down engine, turn keyswitch “Off” and
wait 90 seconds for the steering accumulator
to bleed down.
g. Remove test equipment and reconnect all
hoses to their proper location.
Bleeddown Manifold
3. Disconnect hoist pilot valve return line (15, Fig-
ure 10-4). Plug the port on bleeddown manifold.
Hydraulic tank oil level is above the level of this
return line. It is necessary to draw a vacuum on
the hydraulic tank to prevent a large amount of
oil from draining out of the tank with the return
line disconnected from the bleeddown manifold.
4. Draw a vacuum on the hydraulic tank to prevent
oil loss. Disconnect return line to tank from
bleeddown manifold (11, Figure 10-4). Connect
the hoist pilot valve return line (15) and the
return line to tank (11) together.
5. Remove vacuum on the hydraulic tank. Start
engine. Allow accumulator to fill up. Measure
leakage from the return hose fitting in the bleed-
down manifold. Maximum allowable leakage
from the bleeddown manifold is 33.0 in.
3
(541
ml) per minute. If leakage is excessive, the fol-
lowing components should be replaced until the
leakage is within the allowable limits:
• Bleeddown Solenoid
• System Relief Valve (4000 psi)
• Piloted Check Valve
6. After test is complete, shut down the engine with
the Shut Down switch on the console next to the
seat. Do not use the keyswitch to shut down
the engine.
If keyswitch is used, all the oil in the accumulator
will come out the port that was used to check
manifold leakage.
7. Before removing plugs on bleeddown manifold
or disconnecting lines that have been con-
nected, be sure to draw a vacuum on the
hydraulic tank to prevent spillage. Remove test
equipment and reconnect all hoses to their
proper location.
8. Turn key switch to the “OFF” position to allow
steering accumulators to bleed down.