JLG 601S, Service And Maintenance Manual

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SECTION 5 - HYDRAULICS
3120746 – JLG Lift – 5-25
DO NOT START THE ENGINE UNLESS PUMP IS IN THE NEUTRAL
POSITION (0 DEGREES SWASHPLATE ANGLE). TAKE PRECAU-
TIONS TO PREVENT MACHINE MOVEMENT IN CASE PUMP IS
ACTUATED DURING INITIAL START-UP.
"Jog" or slowly rotate the engine until charge pressure
starts to rise. Start the engine and run at the lowest possi-
ble RPM until charge pressure has been established.
Excess air should be bled from the system lines as close
to the motors as possible.
NOTE: With the engine on low idle, "crack", (loosen-don't
remove), the system lines at the motor(s). Continue
to run the engine at low idle and tighten the system
lines as soon as oil is observed to leak from them.
When oil is observed to "leak" at the motor the line is
full, the air has been purged, and the system hoses
should be retightened to their specified torque.
Once charge pressure has been established, increase
speed to normal operating RPM. Charge pressure should
be as indicated in the pump model code. If charge pres-
sure is inadequate, shut down and determine the cause
for improper pressure.
INADEQUATE CHARGE PRESSURE WILL AFFECT THE OPERA-
TOR'S ABILITY TO CONTROL THE MACHINE.
Shut down the engine and connect the external control
input signal. Also reconnect the machine function(s), if
disconnected earlier. Start the engine, checking to be cer-
tain the pump remains in neutral. With the engine at nor-
mal operating RPM, slowly check for forward and reverse
machine operation.
Charge pressure may slightly decrease during forward or
reverse operation. Continue to cycle slowly between for-
ward and reverse for at least five minutes.
Shut down engine, remove gauges, and plug ports.
Check reservoir level and add filtered fluid if needed.
The machine is now ready for operation.