JLG 4013PS Service Manual - Manual (Page 132)

Hydraulic System
8-22 3508PS, 3509PS, 3512PS, 3513PS, 4008PS, 4009PS, 4012PS, 4013PS, 4017PS, 40.8, 40.9
f. Main Control Valve Installation
1. Loosely install the four main control valve mounting
bolts through bracket on the inside rail of the engine
bay.
2. Install the main control valve onto the bracket,
aligning the bolts with the holes in the end sections
of the main control valve. Slide the main control
valve into position, and tighten the bolts.
3. Prime the main control valve by filling the inlet
openings with fresh, filtered hydraulic oil from a
clean container, before attaching the hoses.
4. Use new oiled o-rings as required. Uncap and
connect all hoses, clamps, etc. to the main control
valve.
5. Check the routing of all hoses, wiring 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.
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 for leaks and check the level of the hydraulic
oil in the reservoir. Shut the engine OFF.
9. Wipe up any hydraulic oil spillage in, on, near and
around the machine, work area and tools.
10. Close and secure the engine cover.
11. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
g. Main Control Valve Test
Conduct a pressure check of the hydraulic system in its
entirety. Adjust pressure(s) as required. Refer to Section
8.4.1, “Hydraulic Pressures.”
8.9.2 Service Brake Valve
The service brake valve is at the base of the steering
column support, concealed by the lower dash cover.
The service brakes themselves are part of the axles (the park
brake is part of the front axle only). Refer to Section 5, “Axles,
Drive Shafts, Wheels and Tires,” for further information.
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 control lever 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, stating that the
machine should not be operated.
3. Open the engine cover. Allow the system fluids to
cool.
4. Properly disconnect the battery.
5. Remove the necessary dash panels.
6. Label, disconnect and cap all hydraulic hoses and
fittings on the service brake valve (8).
7. Disconnect the pin holding the yoke to the brake
pedal arm.
8. Remove the capscrews and lockwashers mounting
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 with the lockwashers
and capscrews to mount the brake valve to the
steering column support.
2. Align the yoke on the brake valve with the brake
pedal arm. Insert the pin and clip into place being
sure there is a small amount of play between the
pedal and the brake plunger.
MZ1980
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