JLG 1250AJP Service Manual - Manual (Page 401)

SECTION 5 - HYDRAULICS
3121171 – JLG Lift – 5-47
5.7 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.
To ensure all pressures are set correctly, the following pro-
cedures must be followed in order.
1. All applicable steps in Section 5.10, Drive & Function
Pump Start Up Procedures must be followed.
2. Set up of the function pump.
3. Adjustments made at the main valve bank.
4. Adjustments made at the platform valve.
Set Up of the Function Pump
STAND BY PRESSURE OR LOW PRESSURE RELIEF -
450 PSI (31 BAR)
1. Install a low pressure gauge at port MP1 of the main
valve block capable of reading 450 psi (31 bar).
2. Start the engine from the ground control. The gauge
should read 425-475 psi (29.3-32.75 bar).
3. To make an adjustment to this pressure, go to the
engine compartment, locate the function pump. The
stand by adjustment is the outside adjustment, clos-
est to the turntable.
4. Using a 17mm wrench, remove the cover nut. Be
careful not to lose the o-ring washer inside the cover
nut.
5. Loosen the jam nut at the setscrew with the 17mm
wrench.
6. Using a 3mm allen wrench, adjust clockwise to
increase or counterclockwise to decrease.
7. After adjusting the pressure, tighten the jam nut and
the cover nut.
8. Start the engine and verify the gauge reads 425-475
psi (29.3-32.75 bar).
REXROTH PUMP
SAUER PUMP