JLG 110HX ANSI Service Manual - Manual (Page 44)

SECTION 2 - PROCEDURES
2-20 – JLG Lift – 3120636
6. Remove temporary hoses from level cylinder and
cap them. Plug cylinder ports.
7. Using slings, restrain level cylinder.
8. Remove retaining plate and bolts from upright cylin-
der attach pin.
9. Using an appropriate brass drift, drive out the
upright attach pin. Carefully remove restraining
slings and remove level cylinder from boom
Master Level Cylinder Installation
1. With the boom positioned at horizontal and properly
supported, place the master level cylinder in posi-
tion on the boom and secure in place using slings.
2. Align barrel end bushing with pin attach blocks in
turntable upright and install upright attach pin using
appropriate brass drift. Secure pin with retaining
plate and retaining plate bolts.
3. Remove caps from temporary hydraulic lines and
attach to level cylinder ports. Using auxiliary power,
activate swing function and extend cylinder rod until
rod bushing aligns with boom lift cylinder rod end
attach bushing.
4. Using an appropriate brass drift drive the rod attach
pin through the aligned bushings of the cylinder rod
and boom lift cylinder rod end attach plate, taking
care to align holes for bolt attachment. Secure rod
end attach pin with bolt, lockwasher and nut.
5. Remove restraining slings from level cylinder.
6. Remove temporary hydraulic lines from cylinder
ports and turntable swing motor hydraulic supply.
Reattach hydraulic supply to swing motor.
7. Remove caps from cylinder hydraulic lines and cor-
rectly install lines to cylinder.
8. Remove boom support. Place boom in stowed posi-
tion. Check hydraulic fluid level and adjust accord-
ingly.
2.11 CYLINDER REPAIR
NOTE: The following are general procedures that apply to
all of the cylinders on this machine. Procedures that
apply to a specific cylinder will be so noted.
Disassembly
DISASSEMBLY OF THE CYLINDER SHOULD BE PERFORMED ON
A CLEAN WORK SURFACE IN A DIRT FREE WORK AREA.
1. Connect a suitable auxiliary hydraulic power source
to the cylinder port block fitting.
DO NOT FULLY EXTEND CYLINDER TO END OF STROKE.
RETRACT CYLINDER SLIGHTLY TO AVOID TRAPPING PRES-
SURE.
2. Operate the hydraulic power source and extend the
cylinder. Shut down and disconnect the power
source. Adequately support the cylinder rod, if appli-
cable.
3. If applicable, remove the cartridge-type holding
valve and fittings from the cylinder port block. Dis-
card o-rings.
4. Place the cylinder barrel into a suitable holding fix-
ture.
5. Tap around outside of cylinder head retainer, if appli-
cable, and/or cylinder head gland with a suitable
hammer to shatter loctite.
6. Using a suitable spanner wrench or chain wrench,
loosen the cylinder head retainer, if applicable, and/
or cylinder head gland, and remove from cylinder
barrel. If using a chain wrench, keep wrench toward
outside (rod side) of gland nut to avoid distorting
threads.
7. Attach a suitable pulling device to the cylinder rod
port block end or cylinder rod end, as applicable.
EXTREME CARE SHOULD BE TAKEN WHEN REMOVING THE CYL-
INDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD OFF-
CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON AND
CYLINDER BARREL SURFACES.
RO
D
S
U
P
P
O
RT
SUPPORT
TABLE
ROD CLAMP
PROTECTED
BARREL CLAMP
Figure 2-6. Cylinder Barrel Support