JLG G6-42A Service Manual - Manual (Page 150)

Hydraulic System
8-22 G6-42A, G9-43A, G10-43A
b. Steer Select Manifold and Valve Disassembly,
Cleaning, Inspection and Assembly
1. Place the steer select assembly on suitable
work surface.
2. Separate steer select valve from manifold by
removing four socket head capscrews. Discard
four o-rings.
3. Remove solenoid valves and cartridges from steer
select housing.
4. Clean all components with a suitable cleaner
before inspection.
5. Inspect the solenoid cartridges for proper operation.
Check by shifting the spool to ensure that it is
functioning properly. Check that the spring is intact.
Inspect the cartridge interior for contamination.
6. Inspect internal passageways of the steer select
manifold and valve for wear, damage, etc. If inner
surfaces of the manifold DO NOT display an ultra-
smooth, polished finish, or components are
damaged in any way, replace the manifold or
appropriate part. Often, dirty hydraulic fluid causes
failure of internal seals and damage to the polished
surfaces within the secondary function manifold.
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.
7. Install the solenoid valves and cartridges in the steer
select housing.
8. Attach steer select valve to manifold using four new,
oiled o-rings and the four socket head capscrews.
c. Steer Select Valve and Manifold Installation
1. Install steer select valve to the mounting plate under
the left front side of the frame using the two bolts.
2. Connect all the hydraulic hoses, fittings, solenoid
wire terminal leads, etc., to the steer select valve
3. 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 hose clamps.
4. Properly connect the battery.
5. Start the engine and run at approximately 1/3-1/2
throttle for about one minute without moving the
machine or operating any hydraulic functions.
6. Inspect 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. Wipe up any hydraulic fluid spillage in, on, near and
around the machine, work area and tools.
8. Close and secure the engine cover.
9. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
d. Steering Test
Refer to Section 8.4.1, “Hydraulic Pressures.”
1. Conduct pressure check of steering hydraulic circuit.
2. Check each steering mode for proper function.
8.7.6 Outrigger Valve (G10-43A)
a. Outrigger Valve Removal
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, raise 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.
3. Open engine cover. Allow system fluids to cool.
4. Properly disconnect battery.
5. Remove the cover over the outrigger valve.
6. Label, disconnect and cap the hydraulic hoses
connected to the outrigger control valve (5). Cap all
fittings to keep dirt & debris from entering the
hydraulic system.
OAL0070
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