JLG 80HX_HX+6_HXER ANSI Service Manual - Manual (Page 107)

SECTION 5 - HYDRAULICS
3120271 – JLG Lift – 5-15
11. Install the trunnion pin covers on each side of boom.
12. Carefully install the telescope cylinder barrel attach
pin into the base boom.
13. Install the snap rings that retain the telescope cylin-
der pin to the base boom.
14. Remove applicable hydraulic line and port caps and
correctly connect the hydraulic lines to the tele-
scope cylinder. Ensure all hoses are correctly
routed.
15. Install the boom end cover.
16. Activate hydraulic system.
17. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
18. Cycle (extend/retract) boom several times, then
torque boom chains to 40 ft. lbs. (2.76 Bar). See
Boom Chains in Section 4, Boom & Platform for cor-
rect torquing procedure.
19. Check fluid level of hydraulic tank and adjust as nec-
essary.
Boom Lift Cylinder Removal
1. Place the machine on a flat and level surface. Start
the engine and place the boom in a horizontal posi-
tion. Shut down the engine and prop the boom. (See
Figure 5-2.)
2. Remove the hardware retaining the cylinder rod
attach pin to the boom. Using a suitable brass drift,
drive out the cylinder rod attach pin.
3. Using auxiliary power, retract the lift cylinder rod
completely.
4. Disconnect, cap and tag the boom lift cylinder
hydraulic lines and ports.
5. Remove barrel end attach pin retaining hardware.
Using a suitable brass drift drive out the barrel end
attach pin from the turntable upright.
6. Remove the cylinder from the boom and place in a
suitable work area.
Boom Lift Cylinder Installation
1. Install the lift cylinder in place using suitable slings
or supports, aligning the attach pin mounting holes
on the turntable upright.
2. Using a suitable drift, drive the barrel end attach pin
through the mounting holes in the lift cylinder and
the turntable upright. Secure in place with the pin
retaining hardware.
3. Remove the cylinder port plugs and hydraulic line
caps and correctly attach the lines to the cylinder
ports.
4. Using auxiliary power, extend the cylinder rod until
the attach pin hole aligns with those in the boom.
Using a suitable drift, drive the cylinder rod attach
pin through the aligned holes, taking care to align
the grooved pin holes. Secure the pin in place with
attaching hardware.
5. Remove the boom prop and overhead crane. Acti-
vate the hydraulic system.
6. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
7. Check the fluid level of the hydraulic tank and adjust
as necessary.
5.6 TELESCOPE CYLINDER ECCENTRIC
BUSHING
IMPORTANT
RELOCATE ALTERNATE SETSCREW HOLE ONLY WHEN REPLAC-
ING ECCENTRIC BUSHING.
When replacing the eccentric bushings, drill 5/16" dia. x 3/
4" deep, tap 3/8-16NC x 9/16" deep for a new setscrew
(bushing to boom) either above or below original holes.
Allow enough room between the holes for strength while
staying on the thick side of the bushing. (See Figure 5-10.)
5.7 HYDRAULIC PUMP W/HAYES PUMP
DRIVE COUPLING LUBRICATION
Any time pump or pump drive coupling is removed coat
pump and drive coupling splines with Lithium Soap Base
Grease (TEXACO CODE 1912 OR EQUIVALENT) prior to
assembly.
Figure 5-10. Telescope Cylinder Eccentric Bushing