Hydraulic Tank; Pressure Setting Procedure; Set Up Of The Function Pump - JLG 1200SJP Service Maintenance Manual

5.3 HYDRAULIC TANK

The hydraulic tank has a capacity of 55 gallons (208 liters) and
includes the hydraulic return filter and two suction strainers. It
is normal for the oil level to appear low when the boom is
raised and should only be checked with the machine on level
ground and with the boom fully retracted and lowered. The
hydraulic oil should be maintained at the full level as shown by
the decal and hydraulic oil level gauge located on the side of
the tank as shown in Figure 5-27., Hydraulic Oil Level Gauge.
This decal shows the proper full level for both hot and cold oil.
Do not fill the hydraulic tank past the appropriate full mark.
Overfilling can cause the oil to overflow from the top of the
hydraulic tank during emergency lowering operations.
Figure 5-27. Hydraulic Oil Level Gauge
3121142
FULL LEVEL (HOT OIL)
FULL LEVEL (COLD OIL)
– JLG Lift –

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.
To ensure all pressures are set correctly, the following proce-
dures must be followed in order.
1. All applicable steps in Section 5.7, 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
HIGH PRESSURE RELIEF - 3400 PSI (234.4 BAR)
1. Install a high pressure gauge at the MP port of the main
valve block.
2. Using a screwdriver, remove the Din connector from the
lift down coil.
3. Activate lift down. The gauge should read 3400 psi (234
bar).
SECTION 5 - HYDRAULICS
5-25