JLG 450A_AJ Series II Service Manual - Manual (Page 331)

SECTION 5 - HYDRAULICS
3121180 – JLG Lift – 5-41
Install a 1000 psi (60 bar) pressure gauge in charge pres-
sure gauge port to monitor charge pressure during start-up.
It is recommended the external control input signal, (elec-
trical connections for EDC), be disconnected at pump
control until after initial start-up. This ensures pump
remains in its neutral position.
DO NOT START 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 engine until charge pressure starts
to rise. Start engine and run at lowest possible RPM until
charge pressure is established. Excess air should be bled
from system lines as close to motors as possible.
NOTE: With engine on low idle, ”crack”, (loosen-don't
remove), system lines at motor(s). Continue to run
engine at low idle and tighten system lines as soon
as oil is observed to leak from them. When oil is
observed to ”leak” at motor, line is full, air has been
purged, and system hoses should be retightened to
their specified torque.
Once charge pressure is 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 determine cause of improper
pressure.
INADEQUATE CHARGE PRESSURE WILL AFFECT OPERATOR'S
ABILITY TO CONTROL THE MACHINE.
Shut down engine and connect the external control input
signal. Also reconnect the machine function(s), if discon-
nected earlier. Start engine, checking the pump remains in
neutral. With engine at normal operating RPM, slowly
check 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.
Machine is now ready for operation.