JLG 600SC_660SJC Service Manual - Manual (Page 191)

SECTION 5 - HYDRAULICS
3121607 – JLG Lift – 5-47
5.9 PRESSURE SETTING PROCEDURES
COLD TEMPERATURES HAVE A SIGNIFICANT IMPACT ON PRESSURE READINGS.
JLG INDUSTRIES, INC. RECOMMENDS OPERATING THE MACHINE UNTIL THE
HYDRAULIC SYSTEM HAS WARMED TO NORMAL OPERATING TEMPERATURES
PRIOR TO CHECKING PRESSURES. JLG ALSO RECOMMENDS USING A CALI-
BRATED GAUGE. PRESSURE READINGS ARE ACCEPTABLE IF WITHIN +/- 5% OF
SPECIFIED PRESSURES.
Main Relief
1. Install pressure gauge at quick disconnect on port MP
on main valve.
2. With aid of an assistant, activate telescope in.
3. While monitoring pressure gauge, adjust main relief to
3000 PSI (206.85 Bar). Turn adjuster clockwise to
increase pressure or counterclockwise to decrease pres-
sure.
Lift Down
1. Install pressure gauge at quick disconnect in port MP on
main valve.
2. With aid of an assistant, activate lift down.
3. While monitoring pressure gauge, adjust lift down relief
to 1500 PSI (103 Bar). Turn adjuster clockwise to increase
pressure or counterclockwise to decrease pressure.
Swing
NOTE: Left and right swing pressures are set with one adjustment.
1. Install pressure gauge at quick disconnect on port MP
on main valve.
2. Lock the turntable using the turntable lock.
3. With the aid of an assistant, activate swing left or right
4. While monitoring pressure gauge, adjust swing relief to
1700 PSI (117 Bar). Turn adjuster clockwise to increase
pressure or counterclockwise to decrease pressure.
Platform Level Up
NOTE: Pressure is trapped at port M3 and must be released before
installing pressure gauge.
1. Activate level down to end of stroke to release pressure.
Install pressure gauge at quick disconnect on port M3
on main valve after releasing pressure.
2. With aid of an assistant, activate level up.
3. While monitoring pressure gauge, adjust level up relief
to 2800 PSI (193 Bar). Turn adjuster clockwise to increase
pressure or counterclockwise to decrease pressure.
Platform Level Down
NOTE: Pressure is trapped at port M4 and must be released before
installing pressure gauge.
1. Activate level up to end of stroke to release pressure.
Install pressure gauge at quick disconnect on port M4.
2. With the aid of an assistant, activate level down.
3. While monitoring pressure gauge, adjust the level up
relief to 1800 PSI (124 Bar). Turn the adjuster clockwise
to increase pressure or counterclockwise to decrease
pressure.
Jib Up
1. Install pressure gauge in M port on jib block.
2. With aid of an assistant, activate jib up.
3. While monitoring pressure gauge, adjust jib up relief to
1500 PSI (103 Bar). Turn adjuster clockwise to increase
pressure or counterclockwise to decrease pressure.
Jib Down
1. Install pressure gauge on the M port on jib block.
2. With aid of an assistant, activate jib down.
3. While monitoring pressure gauge, adjust jib down relief
to 1200 PSI (82 Bar). Turn adjuster clockwise to increase
pressure or counterclockwise to decrease pressure.