Komatsu 830E-AC Shop Manual page 775

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 43°C (110°F) or higher before
performing leakage tests.
Steering Control Unit & Flow Amplifier
1. Shift the directional control lever to PARK. Turn
the key switch OFF to stop the engine. Wait 90
seconds for steering accumulator to bleed
down. Turn steering wheel to be sure no pres-
sure remains.
2. To check leakage from the steering control unit
and the flow amplifier:
a. Disconnect steering control unit tank (return)
line at the flow amplifier ("T" port, Figure 10-
2). Plug the "T" port opening on flow ampli-
fier.
b. Disconnect flow amplifier return hose (from
"HT" port) at the bleed down manifold. Cap
fitting on bleed down manifold
c. Start engine and run at low idle. DO NOT
TURN STEERING WHEEL WHEN RETURN
HOSES ARE DISCONNECTED.
d. Measure leakage from steering control unit
tank line. Leakage not to exceed 164 ml (10
3
in. ) per minute. If leakage is excessive,
replace steering control unit.
L10028
e. Measure leakage from the flow amplifier
f. Turn key switch OFF to stop the enigne and
g. If further leak testing is required, continue to
Bleeddown Manifold
3. With hoses still disconnected as in Step 2, dis-
connect hoist pilot valve return line (15, Figure
10-4) at the bleed down manifold. Plug the fit-
ting on bleed down 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 hose to tank from
bleeddown manifold (11, Figure 10-4). Using
adapters, connect the hoist pilot valve return
hose (15) and the return line to tank hose (11)
together.
Hydraulic Check-out Procedure
return hose (from the "HT" port). Maximum
allowable leakage is 820 m (l50 in.
minute. If leakage is excessive, replace flow
amplifier.
wait 90 seconds for the steering accumulator
to bleed down.
Step 3. Or, remove test equipment and
reconnect all hoses to their proper location.
3
) per
L10-7