Service Manual Owner's manual

SECTION 4 - BASE COMPONENTS
3121222 – JLG Lift – 4-33
Hydraulic System Pressure Settings
Perform final hydraulic pressure setting with oil at normal
operating temperature. If pressure is set when cold, func-
tion may not operate properly after oil has warmed.
Turning relief adjustment screw clockwise - increases
pressure, turning adjustment screw counterclockwise -
decreases pressure. DO NOT EXCEED MAXIMUM
PRESSURE SETTINGS. (See Figure 4-13.)
1. To check the lift pressure, attach pressure gauge to
the check port on top of the valve body.
To check steer pressure remove either the left or
right steer hose fitting on the valve body and plumb
a pressure gauge at that point.
2. Power up machine, warm up oil to normal operating
temperature.
3. Check initial pressure for each function, lift and
steering.
4. Adjust pressure relief according to settings shown in
Table 4-2. Lift pressure setting must be adjusted to
raise the maximum capacity allowed in the platform
with the mast fully extended. Do not exceed the
MAXIMUM pressure settings.
Table 4-2. Hydraulic System - Pressure Settings
1230ES
MAXIMUM PRESSURE
SETTING
Main 1600 PSI (110 Bar)
Steer - Left/Right 1250 PSI (86 Bar)
Table 4-3. Hydraulic Pump - Solenoid Specifications
Component Coil Rating
Lift-Up Solenoid 28 Ohm
Steer - Left/Right Solenoid 33 Ohm
Figure 4-13. Relief Pressure Setting Locations
1. Pump Valve Body
2. Steering Right Pressure Relief
3. Steering Left Pressure Relief
4. Main Pressure Relief
5. Pressure Gauge Check
Port