JLG 4017PS Service Manual - Manual (Page 88)

Cab and Covers
4-4 3706PS, 3707PS, 4014PS, 4017PS, 33.7, 37.6, 37.7
4.3.2 Steering Column/Orbitrol Valve
a. Steering Column and Orbitrol Valve Removal
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, lower the boom,
place the travel select lever in the (N) NEUTRAL
position, engage the parking brake and turn the
engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel.
3. Open the engine cover. Allow the system fluids to
cool.
4. Properly disconnect the battery.
5. Remove the lower dash panel in the cab.
6. Remove the protective cover from the front of the
cab.
7. Label, disconnect and cap the hydraulic hoses
attached to the orbitrol valve (1).
8. Remove the steering wheel (2). Refer to Section
4.3.1, “Steering Wheel.”
9. Disconnect and remove the accessory control lever
(3), and if equipped, transmission control lever (4).
Disconnect the control lever(s) harness from the
main cab harness.
10. Have an assistant hold the orbitrol valve from the
outside of the cab. Remove the four bolts (5)
securing the orbitrol valve to the cab.
11. Remove the steering column (6) through the dash
panel opening.
Note: DO NOT disassemble the orbitrol valve. The
orbitrol valve is not serviceable and must be replaced in
its entirety, if defective.
b. Steering Column and Orbitrol Valve Installation
1. Install the steering column to its original orientation
in the cab.
2. Have an assistant hold the orbitrol valve in its
original orientation from outside the cab. Install the
steering column to the valve with the previously
removed hardware.
3. Install the accessory control lever, and if equipped,
transmission control lever. Connect the control
lever(s) harness connector to the main cab harness
and install the steering wheel assembly.
4. Uncap and connect the previously labeled hydraulic
hoses to the orbitrol valve.
5. Carefully examine all connections one last time
before engine start-up. Rectify any faulty conditions.
6. Properly connect the battery.
7. Start the engine and check the operation of steering
system. Check for hydraulic fluid leaks. Check the
hydraulic fluid level in the tank and add fluid as
required.
8. Install the protective cover to the front of the cab.
9. Install the lower dash panel in the cab.
10. Close and secure the engine cover.
11. Remove the Do Not Operate Tag from the ignition
key switch and the steering wheel.
c. Steering Test
Conduct a pressure check of the steering hydraulic
circuits at the main control valve. Refer to Section 8.4.1,
“Pressure Checks and Adjustments.”
4.3.3 Service Brake
a. Brake Valve Removal
Refer to Section 8.10.3, “Service Brake Valve,” for
removal information.
b. Brake Valve Installation
Refer to Section 8.10.3, “Service Brake Valve,” for
installation information.
MAM3930
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