Main Valve Block Pressure Settings; Main Relief; Main Lift Down; Swing - JLG 660SJ Service And Maintenance Manual

5.9 MAIN VALVE BLOCK PRESSURE SETTINGS

Refer to Figure 5-88., Main Control Valve Block Assembly - 4WS
Deutz D2011 and GM Engines (SN 0300181891 to Present),
Deutz TD2.9L4 Engines (SN 0300188199 to Present)
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 high pressure gauge in port MP (11).
2. Activate telescope in.
3. Adjust main relief valve (6) to 3000 psi (207 bar). Turn
adjuster clockwise to increase or counterclockwise to
decrease pressure.

Main Lift Down

1. Install high pressure gauge in port MP (11).
2. Activate Main lift down.
3. Adjust lift down relief (6) to 2000 psi (138 bar). Turn
adjuster clockwise to increase pressure or counterclock-
wise to decrease pressure.
NOTE: This pressure allows for system pressure drop and should
equal 1500 psi (103 bar) at the work port.

Swing

NOTE: Left and right swing pressures are set with one adjustment.
1. Install high pressure gauge in port MP (11).
2. Lock turntable with turntable lock pin.
3. Activate swing left or right
4. Check both directions of swing and adjust lowest pres-
sure reading at swing relief (6) to 1700 psi (117 bar). Turn
adjuster clockwise to increase pressure or counterclock-
wise to decrease pressure.

2-Wheel Steer

1. Install high pressure gauge in port MP (11).
2. Activate steer left and right.
3. Adjust front steer relief valves (7) to 2050 psi (141 bar) in
both directions. Turn adjuster clockwise to increase
pressure or counterclockwise to decrease pressure.
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NOTE: This pressure allows for system pressure drop and should
equal 1800 psi (124 bar) at the work port.
4-Wheel Steer
1. Install pressure gauge in port MP (11).
2. Activate front wheel steer left and right.
NOTE: Rear steer relief cartridges are preset and not field adjust-
able.
3. Adjust front steer relief valves (7) to 2700 psi (186 bar) in
both directions. Turn adjuster clockwise to increase
pressure or counterclockwise to decrease pressure.
5.10 PLATFORM (SLAVE) VALVE BLOCK PRESSURE
SETTINGS
Refer to Figure 5-90., Location of Components - Main Control
Valve Deutz D2011 and GM Engines (SN 0300181891 to Pres-
ent), Deutz TD2.9L4 Engines (SN 0300188199 to Present)

Platform (Slave) Level Extend

1. Install high pressure gauge in port M1 (1).
2. Activate level up to end of stroke.
3. Adjust level up relief (6) to 2800 psi (193 bar). Turn
adjuster clockwise to increase pressure or counterclock-
wise to decrease pressure.

Platform (Slave) Level Retract

1. Install high pressure gauge at quick disconnect on port
M2 (2).
2. Activate level down to end of stroke.
3. Adjust level down relief (5) to 1800 psi (124 bar). Turn
adjuster clockwise to increase pressure or counterclock-
wise to decrease pressure.

Articulating Jib

NOTE: Relief pressure is bi-directional, but can only be read in one
direction.
1. Install high pressure gauge in port M3 (12).
2. Activate jib extend to end of stroke.
3. Adjust jib relief (9) to 1500 psi (103 bar). Turn adjuster
clockwise to increase pressure or counterclockwise to
decrease pressure.
– JLG Lift –
SECTION 5 - HYDRAULICS
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