SkyTrak 8042 Service Manual - Manual (Page 176)

Hydraulic System
8-32 6036, 6042, 8042, 10042, 10054
functioning properly. Check that the spring is intact.
Inspect the cartridge interior for contamination.
4. Inspect internal passageways and the extend
lockout valve overall for wear, damage, etc. If inner
surfaces of the component DO NOT display an ultra-
smooth, polished finish, or are damaged in any way,
replace the extend lockout valve. Often, dirty
hydraulic fluid causes failure of internal seals and
damage to the polished surfaces within the valve.
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.
5. Install the solenoid valve.
6. Install the pressure sensing valve. Torque to 65 lb-ft
(88 Nm).
c. Extend Lockout Valve Installation
1. Place the extend lockout valve into position on the
mounting plate on the machine frame.
2. Install the bolt and nut securing the valve to the
frame.
3. Connect all the previously labeled hydraulic hoses,
fittings, solenoid wire terminal leads, etc., to the
outrigger valve.
4. Check the routing of all hoses and wiring for sharp
bends or interference with any rotating members,
and install tie wraps and/or protective conduit as
required. Tighten all hose clamps.
5. Properly connect the battery.
6. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
7. 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.
8. 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.
9. Wipe up any hydraulic fluid spillage in, on, near and
around the machine, work area and tools.
10. Install the transmission covers.
11. Close and secure the rear door.
d. Extend Lockout Valve Test
Conduct a test of the extend lockout valve.
1. Park the machine on a firm, level surface.
2. With the boom fully retracted and lowered, lower the
outriggers.
3. Extend the boom to 54 ft. The boom should extend
fully and should not stop at 42 ft.
8.8 HYDRAULIC CYLINDERS
8.8.1 General Cylinder Instructions
a. Cylinder Removal
1. Remove any attachment from the machine. Park the
machine on a firm level surface and fully retract the
boom. Allow sufficient work space around the
hydraulic cylinder being removed. Support the boom
if the lift/lower cylinder is being removed. Place the
travel select lever in (N) NEUTRAL, engage the park
brake, shut the engine OFF and chock wheels.
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 rear door. Allow the system fluids to cool.
4. Label, disconnect and cap or plug hydraulic hoses in
relation to the cylinder.
5. Attach a suitable sling to an appropriate lifting device
and to the cylinder. Make sure the device used can
actually support the cylinder.
6. Remove the lock bolt and/or any retaining clips
securing the cylinder pins. Remove the cylinder pins.
7. Remove the cylinder.
8. Wipe up any hydraulic fluid spillage in, on, near and
around the machine, work area and tools.