JLG 4017RS Service Manual - Manual (Page 143)

8-13 3614RS, 4017RS
Hydraulic System
8.9.2 Service Brake Valve
a. Service Brake Valve Removal
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, lower the boom, place
the transmission in (N) NEUTRAL, engage the park brake
and shut 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 access covers from the outside of the cab.
6. Label, disconnect and cap all hoses attached to the
service brake valve (1).
7. Remove the cover panel in the cab (2).
8. Disconnect and remove the brake pedal (3).
9. Remove the two nuts (4) securing the service brake
valve to the cab.
10. Remove the valve through the front of the cab.
Note: DO NOT disassemble the service brake valve. The service
brake valve is not serviceable and must be replaced in its
entirety, if defective.
b. Service Brake Valve Installation
1. Install the service brake valve to its original orientation
in the cab. Secure with the previously used hardware.
2. Install the service brake pedal.
3. Uncap and connect the previously labeled hydraulic
hoses to the service brake valve.
4. Check the routing of all hoses, and tubing for sharp
bends or interference with any rotating members, and
install tie wraps and/or protective conduit as required.
Tighten all tube and hose clamps.
5. Properly connect the battery.
6. Start the engine and run at approximately one-third to
one-half throttle for about one minute, without moving
the machine or operating any hydraulic functions.
7. Inspect the service brake valve and connections for
leaks, and check the level of the hydraulic fluid in the
reservoir. Shut the engine OFF.
8. Wipe up any hydraulic fluid spillage in, on, near and
around the machine, work area and tools.
9. Install the cover panel in the cab.
10. Install the access covers to the outside of the cab.
11. Close and secure the engine cover.
12. Remove the Do Not Operate Tag from the ignition key
switch and the steering wheel.
8.9.3 Service Brake Bleeding
Carefully bleed the brake lines as soon as the brake valve is
installed in the machine. Air in the system will not allow the
brakes to apply properly. There are two brake bleeder
locations on the front and rear axles. Work with an assistant
to perform this procedure.
1. Place the travel select lever in (N) NEUTRAL, engage the
park brake, and start the engine.
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