Pressure Setting Procedure; Main Relief; Telescope In; Telescope Out - JLG T500J Service And Maintenance Manual

SECTION 5 - BASIC HYDRAULIC INFORMATION & SCHEMATICS
5.4

PRESSURE SETTING PROCEDURE

Cold temperatures have a significant impact on pressure read-
ings. JLG Industries Inc. recommends operating the machine
until the hydraulic system has warmed to normal operating
temperatures prior to checking pressures. JLG Industries Inc.
also recommends the use of a calibrated gauge. Pressure read-
ings are acceptable if they are within ± 5% of specified pres-
sures.

Main Relief

1. Install a pressure gauge at the port marker "G" located
on top of the valve block.
2. The telescope "In" relief valve is located below the hand
pump. Screw this in (clockwise) 2 turns.
3. Telescope out about 5 feet. Then telescope in until it
bottoms out. The gauge should read 2700 psi. (186 bar).
4. If adjustment is needed, the main relief adjustment is
located below the "TA" and "TB" ports. To increase, screw
clockwise, to decrease screw counterclockwise.

Telescope In

1. Install a pressure gauge at the port marked "G" located
on top of the valve block.
2. Locate the telescope "In" relief valve below the hand
pump.
3. Telescope out about 5 feet. Then telescope in until it
bottoms out. The gauge should read 2200 psi. (152 bar).
4. To increase, screw clockwise, to decrease screw counter-
clockwise.

Telescope Out

1. Install a pressure gauge at the port marked "G" located
on top of the valve block.
2. Locate the telescope "Out" relief valve located below the
"GA" gauge port.
3. Telescope out until it bottoms out. The gauge should
read 2400 psi. (166 bar).
4. To increase, screw clockwise, to decrease screw counter-
clockwise.

Platform Level Up

1. Install a pressure gauge at the port marked "GA" located
on the left side of the block right next to the telescope
directional valve.
2. Both level relief valves are located on top of the valve
block. The one toward the center is level up.
3. Level up until it bottoms out. The gauge should read
2200 psi (152 Bar).
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4. To increase, screw clockwise, to decrease screw counter-
clockwise.

Platform Level Down

1. Install a pressure gauge at the port marked "GB" located
on the front side of the block right below the hand
pump.
2. Both level relief valves are located on top of the valve
block. The one toward the out side is level down.
3. Level down until it bottoms out. The gauge should read
2000 psi. (138 bar).
4. To increase, screw clockwise, to decrease screw counter-
clockwise.

Swing Right

1. Install a pressure gauge at the port marked "G" located
on top of the block.
2. Lower the boom down into the boom rest to lock the
boom.
3. Activate swing right. The gauge should read 
600 - 800 psi. (41 - 55 bar).
4. The swing right relief valve is located on the left face
next to the swing directional valve. To increase, screw
clockwise, to decrease screw counterclockwise.

Swing Left

1. Install a pressure gauge at the port marked "G" located
on top of the block.
2. Lower the boom down into the boom rest to lock the
boom.
3. Activate swing left. The gauge should read 600 - 800 psi.
(41 - 55 bar).
4. The swing left relief valve is located on the front face
next to the suction port. To increase, screw clockwise, to
decrease screw counterclockwise.

Outrigger Up

1. Install a pressure gauge at the port marked "G" located
on top of the block.
2. Activate jacks up until the cylinders are all bottomed
out. The gauge should read 2500 psi. (172.5 bar).
3. The outrigger relief valve is located on the front face
below the lift push button manual descent valve. To
increase, screw clockwise, to decrease screw counter-
clockwise.
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