JLG G5-18A Service Manual - Manual (Page 116)

Hydraulic System
8-26 G5-18A, 2505H, 25.5
8.12 HYDRAULIC CYLINDERS
8.12.1 General Cylinder Removal
Instructions
1. Park the machine on a firm, level surface, 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. Chock the wheels.
3. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel, stating that the
machine should not be operated.
4. Open the battery and engine covers. Allow the
system fluids to cool.
5. Properly disconnect the battery.
6. Label, disconnect and cap hydraulic hoses in
relation to the cylinder.
7. Attach a suitable sling to an appropriate lifting device
and to the cylinder. Make sure the device used can
actually support the cylinder.
8. Remove the lock bolt and/or any retaining clips
securing the cylinder pins. Remove the cylinder pins.
9. Remove the cylinder.
10. Wipe up any hydraulic fluid spillage in, on, near or
around the machine.
8.12.2 General Cylinder Disassembly
1. Clean the cylinder with a suitable cleaner before
disassembly. Remove all dirt, debris and grease
from the cylinder.
2. Clamp the barrel end of the cylinder in a soft-jawed
vise or other acceptable holding equipment if
possible.
3. If applicable, remove the counterbalance valve from
the side of the cylinder barrel.
4. Extend the rod (5) to allow access to the base of the
cylinder.
5. Using a pin spanner wrench, unscrew the head
gland (6) from the barrel (1). A considerable amount
of force will be necessary to remove the head gland.
Carefully slide the head gland down along the rod
toward the rod eye end, away from the cylinder
barrel.
NOTICE
Avoid using excessive force when clamping the
cylinder in a vise. Apply only enough force to hold the
cylinder securely. Excessive force can damage the
cylinder tube.
NOTICE
DO NOT tamper with or attempt to adjust the
counterbalance valve cartridge. If adjustment is
necessary, replace the counterbalance valve with a
new part.
NOTICE
Protect the finish on the rod at all times. Damage to the
surface of the rod can cause seal failure.
MAH0160
1
4
3
2
6
5
2
1