JLG 120HX ANSI Service Manual - Manual (Page 45)

SECTION 2 - PROCEDURES
3120686 – JLG Lift – 2-25
flange nuts have been tightened too far. Loosen the
“X” nut and repeat steps (3) through (7).
Voltmeter Adjustment
1. Park machine on a flat, level surface. Ensure
machine is level and tires are filled to rated pressure.
2. If engine is not running, turn ignition switch to ON.
3. Connect black lead of voltmeter to ground and red
lead to yellow wire protruding from pot on bottom of
sensor.
4. Adjust leveling nuts to obtain the highest possible
voltage reading.
5. Check voltage at trip point in all four directions. If
voltage reading is not symmetrical, repeat step (4)
above.
2.14 LIMIT SWITCH ADJUSTMENTS
Boom Limit Switch
The boom limit switch is located on the left side of the
base section of the boom. The switch will activate when
the boom is extended past a set point with the axles
retracted. When activated, the switch cuts out Telescope
Out and Lift Up. Adjust the limit switch to trip at 10 feet (3
meters) of boom extension.
Horizontal Cut-Out Switch
The horizontal cut-out switch is located on the right side of
the boom at the boom pivot pin. When activated, the
switch cuts out the High Engine, High Drive and 2 Speed
functions. Adjust the switch to activate when the boom
reaches horizontal.
2.15 THROTTLE CHECKS AND
ADJUSTMENTS - DEUTZ ENGINE
NOTE: Never run fuel tank dry. Diesel engines cannot be
restarted after running out of fuel until fuel system
has been air-vented or “bled” of air. See Deutz
instruction manual for procedure.
1. Disconnect actuator cable from throttle lever. With
the aid of an assistant, start the engine and allow it
to come up to operating temperature. Adjust throttle
lever stop until engine runs at 1800 RPM. Shut down
engine. Reattach actuator cable to throttle lever,
making sure that low (mid) engine setting remains
the same. If necessary, adjust slide pin to contact
low (mid) engine limit switch at 1800 RPM. Shut
down engine.
2. Start the engine from ground controls and allow to
come up to operating temperature. Inside the
ground control terminal box, attach a “hot” wire from
the 12 Volt power (red) wire at the PLATFORM/
GROUND SELECT switch to terminal 1 (brown/black
wire) on the relay circuit card at the top of the
ground control terminal box. This will cause the
engine to run as if HIGH ENGINE and HIGH DRIVE
are activated. Adjust slide pin to contact high engine
limit switch at 2500 RPM. Remove “hot” wire from
terminal 1 and from PLATFORM/GROUND SELECT
switch. Shut down engine.
NOTE: Actuator cable travel must stop slightly before lever
makes contact with throttle lever stop. Failure to do
so will burn out actuator.
2.16 PRESSURE SETTING PROCEDURES
Main Valve
1. Main Relief.
a. Plug pressure gauge into quick-connect on main
valve. Monitor gauge.
b. Bottom out Lift Up function.
c. Loosen nut at main relief and adjust pressure to
3450 psi (238 bar) using an Allen wrench.
Tighten nut.
2. Lift Down Relief.
a. Monitor pressure gauge at quick-connect on
main valve.
b. Bottom out Lift Down function.
c. Loosen nut at lift down relief and adjust pressure
to 1200 psi (83 bar) using an Allen wrench.
Tighten nut.
3. Swing Relief.
a. Monitor pressure gauge at quick-connect on
main valve.
b. Ensure turntable lock is engaged.
c. Bottom out Swing Right function.
d. Loosen nut at swing right relief and adjust pres-
sure to 1200 psi (83 bar) using an Allen wrench.
Tighten nut.
e. Bottom out Swing Left function.
f. Loosen nut at swing left relief and adjust pres-
sure to 1200 psi (83 bar) using an Allen wrench.
Tighten nut.
4. Extend-A-Reach Relief.
a. Monitor pressure gauge at quick-connect on
main valve.