Main High Pressure Relief Valve; Low Pressure Relief Valve; Platform Jib Down Relief Valve - JLG 600SC Service And Maintenance Manual

SECTION 5 - BASIC HYDRAULICS INFORMATION & SCHEMATICS
5.7 PLATFORM VALVE BLOCK PRESSURE SETTING
PROCEDURE
Refer to Figure 5-69. Platform Control Valve Block.

Main High Pressure Relief Valve

1. Install a pressure gauge at port MP1 of the platform con-
trol valve capable of reading pressures up to 5000 psi
(345 bar).
2. Activate platform right or left to the end of stroke and
hold.
3. Adjust Relief Valve (5) to 2950 - 3000 psi 
(204.5 - 207 bar). Turn adjuster clockwise to increase
pressure or counterclockwise to decrease pressure.

Low Pressure Relief Valve

1. Install a pressure gauge at port MP1 of the platform con-
trol valve capable of reading pressures up to 5000 psi
(345 bar).
2. To check or set this adjustment locate the dump direc-
tional valve (10) at the platform manifold (12). Flip the
wires between the two solenoid coils. After the relief has
been set, flip the wires back to their original place.
3. Activate rotate right or left to the end of stroke.
4. Adjust Relief Valve (6) to 2200 ± 50 psi (152 ± 3.5 bar).
Turn adjuster clockwise to increase pressure or counter-
clockwise to decrease pressure.
5-82

Platform Jib Down Relief Valve

1. Install a pressure gauge at port M5-6 of the platform
control valve capable of reading pressures up to 
5000 psi (345 bar).
2. Activate jib down to the end of stroke and hold.
3. Adjust Relief Valve (7) to 1600 - 1650 psi 
(110 - 113.5 bar).
4. This one adjustment will take care of jib up and down.
Jib up will automatically be approximately 50 - 100 psi
(3.5 - 7 bar) higher than jib down. Turn adjuster clock-
wise to increase pressure or counterclockwise to
decrease pressure.
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