5.3 Pressure Setting Procedure; Main Relief; Telescope In; Telescope Out - JLG t350 Service And Maintenance Manual

SECTION 5 - HYDRAULICS

5.3 PRESSURE SETTING PROCEDURE

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
Industries Inc. also recommends the use of a calibrated
gauge. Pressure readings are acceptable if they are within
± 5% of specified pressures.

Main Relief

1. Install a pressure gauge at the port marked "G"
located on top of the valve block.
2. The telescope "In" relief valve is located below the
hand pump. Screw this in (clock wise) 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 clock wise, to decrease screw counter clock
wise.

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
counterclockwise.

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 clock wise, to decrease screw
counter clock wise.
5-10

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).
4. To increase, screw clock wise, to decrease screw
counter clock wise.

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 1200 psi. (83 bar).
4. To increase, screw clock wise, to decrease screw
counter clock wise.

Swing Right

1. Install a pressure gauge at the port marked "G"
located on top of the block.
2. Plug and cap the hose on port "SA" or use the turn-
table stop.
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 clock wise, to decrease screw counter clock
wise.

Swing Left

1. Install a pressure gauge at the port marked "G"
located on top of the block.
2. Plug and cap the hose on port "SB" or use the turn-
table stop.
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 clock
wise, to decrease screw counter clock wise.
– JLG Lift – 3121198