JLG 534D-10 - Manual (Page 144)

Hydraulic System
8.20 534D-9, 534D-10 & 544D
b. Service Brake Valve Installation
1. Install the service brake valve with the four
capscrews, four lockwashers and four nuts onto the
service brake bracket.
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
connect the previously labeled hoses to the service
brake valve.
3. 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.
4. Connect the battery negative (-) cable to the battery
negative (-) terminal.
5. 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.
6. Inspect the service brake valve and connections for
leaks, and check the level of the hydraulic fluid in the
reservoir. Shut the engine OFF.
Note: Check for leaks, and repair as required before
continuing. Add hydraulic fluid to the reservoir as
needed.
7. Replace belly pan.
8. Wipe up any hydraulic fluid spillage in, on, near and
around the machine, work area and tools.
8.8.3 Brake Test
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 four brake
bleeder locations on the front axle with the outer bleeders
being for the service brakes. Work with an assistant to
perform this procedure.
1. Place the travel select lever in (N) NEUTRAL,
engage the park brake.
2. Install a test port line between the charge pressure
test port and the service brake pressure test port.
3. Start the machine, disengage the park brake and
apply the service brake.
Note: If an assistant is not available, block the brake
pedal between the pedal pad and the lower edge of the
dash.
4. Remove the plastic cap from the service brake
bleeder (2). 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.
5. DO NOT open the brake bleeder without holding the
tubing firmly on the bleeder. There is pressure at the
brakes. Carefully open the bleeder with a 12 mm
wrench. Close the brake bleeder when air bubbles
no longer appear in the oil running through the
transparent tubing. Release the brake pedal.
Remove the tubing from the brake bleeder.
6. Conduct a pressure and function check of the
service brake. Refer to Section 8.4.1, “Hydraulic
Pressures.”
Note: The inner bleeder is used to bleed the park brake.
1. Place the travel select lever in (N) NEUTRAL,
engage the park brake.
2. Remove the plastic cap from the park brake bleeder
(3). 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.
3. Start the machine.
4. DO NOT open the brake bleeder without holding the
tubing firmly on the bleeder. There is 380/480 psi
(26/33 bar) at the park brakes. Carefully open the
bleeder with a
12 mm wrench. Close the brake bleeder when air
bubbles no longer appear in the oil running through
the transparent tubing. Remove the tubing from the
brake bleeder.
MX1180
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