JLG G5-18A Service Manual - Manual (Page 118)

Hydraulic System
8-28 G5-18A, 2505H, 25.5
Note: The Crowd cylinder has a spacer that MUST be
installed over the rod AFTER the head gland and
BEFORE the piston head.
3. Fasten the rod eye in a soft-jawed vise, and place a
padded support under and near the threaded end of
the rod (5) to prevent any damage to the rod.
4. Lubricate and slide the head gland (6) over the
cylinder rod (5). Install the piston head (4) on to the
end of the cylinder rod. Loctite
® 243 TM and install the
setscrew (3) in the piston head. Refer to Section
8.12.8, “Hydraulic Cylinder Torque Specifications,”
for tightening guidelines for the piston head and the
set screw.
5. Place the cylinder barrel (1) in a soft-jawed vise or
other acceptable holding equipment if possible.
6. Carefully insert the cylinder rod assembly into the
tube.
7. Screw the head gland (6) into the cylinder barrel (1)
and tighten with a spanner wrench. Refer to Section
8.12.8, “Hydraulic Cylinder Torque Specifications,”
for tightening guidelines for the head gland.
8. If applicable, thread the new counterbalance valve
into the block on the cylinder barrel.
8.12.6 General Cylinder Installation
1. Grease the bushings at the ends of the hydraulic
cylinder. Using an appropriate sling, lift the cylinder
into it’s mounting position.
2. Align cylinder bushing and install pin, lock bolt or
retaining clip.
3. Uncap and connect the hydraulic hoses in relation to
the labels or markings made during removal.
4. Before starting the machine, check fluid level of the
hydraulic fluid reservoir and if necessary, fill to full
mark.
5. Properly connect the battery.
6. Start the machine and run at low idle for about one
minute. Slowly activate hydraulic cylinder function in
both directions allowing cylinder to fill with hydraulic
oil.
7. Inspect for leaks and check level of hydraulic fluid in
reservoir. Add hydraulic fluid if needed.
8. If no leaks are present, operate the hydraulic
function at least twenty times at full throttle to bleed
any air from the cylinder and hoses.
Note: To bleed air from the tilt cylinder, operate the tilt
function along with the lift cylinder as described above.
More operation cycles may be required to clear all air
from the system.
9. Wipe up any hydraulic fluid spillage in, on, near and
around the machine, work area and tools.
10. Close and secure the battery and engine covers.
11. Remove the Do Not Operate Tags from both the
ignition key and the steering wheel.
8.12.7 Steering Cylinders
The steering cylinders are attached to each axle center
housing. Detailed axle service instructions are provided
in the Axle Disassembly & Assembly Manual
(P/N 31200451).
NOTICE
Protect the finish on the rod at all times. Damage to the
surface of the rod can cause seal failure.
NOTICE
Avoid using excessive force when clamping the
cylinder barrel in a vise. Apply only enough force to
hold the cylinder barrel securely. Excessive force can
damage the cylinder barrel.
NOTICE
When sliding the rod and piston assembly into the
cylinder barrel, prevent the threaded end of the
cylinder barrel from damaging the piston head. Keep
the cylinder rod centered within the barrel to prevent
binding.