JLG G5-18A Service Manual - Manual (Page 105)

8-15 G5-18A, 2505H, 25.5
Hydraulic System
6. Label, disconnect and cap the hydraulic hoses
connected to the service brake valve (1). Cap all
fittings and openings to keep dirt & debris from
entering the brake system.
7. Remove the pin and clip (2) securing the service
brake rod to the brake pedal assembly.
8. Remove the two bolts and washers (3) securing the
service brake valve to the steering column support.
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 the steering column
support with the previously removed hardware (3).
Torque as required.
Note: ALWAYS replace seals, o-rings, gaskets, etc.,
with new parts to help ensure proper sealing and
operation. Lubricate seals and o-rings with clean
hydraulic oil.
2. Use new oiled o-rings as required. Uncap and
reconnect the previously labeled hydraulic hoses to
the appropriate locations.
3. Install the pin and clip (2) securing the service brake
rod to the brake pedal assembly.
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. Fill the brake reservoir with Mobil 424 10W-30
hydraulic oil.
6. Properly connect the battery.
7. 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.
8. Inspect the service brake valve and connections for
leaks, and check the brake oil level. Shut the engine
OFF.
9. Replace the necessary dash panels.
10. Wipe up any hydraulic oil spillage in, on, near and
around the machine, work area and tools.
11. Close and secure the battery and engine covers.
12. Remove the Do Not Operate Tags from both the
ignition key and the steering wheel.
c. Service Brake Bleeding Procedure
Carefully bleed the brake lines as soon as the brake valve
is installed on the machine. Air in the system will not allow
the brakes to apply properly. There are two brake bleeder
locations (1) on the front axle. The outside bleeder is
used for the park brake circuit. The inside bleeder is used
for the service brake circuit. Work with an assistant to
perform this procedure.
1. Place the transmission control lever in
(N) NEUTRAL, engage the park brake, and start the
engine.Raise the boom to access the brake
bleeders. Support boom and turn off engine.
2. Remove the plastic cap from the brake bleeder.
Attach one end of a length of transparent tubing over
the brake bleeder. Place the other end of this tubing
in a suitable transparent container that is partially
filled with hydraulic oil. The end of the tubing must be
below the oil level in the container.
MY2161
1
2
3
MY2050
1