Pressure Setting Procedure; P1 Main Relief Valve; P2 Main Relief Valve - JLG H340AJ Service And Maintenance Manual

5.6 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.
To ensure all pressures are set correctly, the following proce-
dures must be followed in order.

1. P1 Main Relief Valve

The P1 main relief valve is a non-adjustable solenoid valve. To
check:
1. Install a pressure gauge at port M1.
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SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS

2. P2 Main Relief Valve

2. Activate Tower Lift Up. At the
end of stroke, the pressure
gauge should read 2500 ±
150 psi (172 ± 10.3 Bar).
3. If the boom cannot be raised to full extension, remove
the hose from port #6. Plug and cap. The setting is non-
adjustable. If the setting is not correct the valve car-
tridge must be replaced.
The P2 main relief valve is a non-adjustable solenoid valve. To
check:
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