JLG X20JP - X600AJ Service Manual - Manual (Page 212)

SECTION 5 - HYDRAULICS
5-34 – JLG Lift – 3121623
Install a 60 bar (or 1000 psi) pressure gauge in the
charge pressure gauge port in order to monitor the
charge pressure during start-up.
It is recommended that the external control input signal,
(electrical connections for EDC), be disconnected at the
pump control until after initial start-up. This will ensure
that the pump remains in its neutral position.
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 pos-
sible 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 retight-
ened 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 pressure is inadequate, shut down and deter-
mine 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
certain the pump remains in neutral. With the engine at
normal 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.