JLG 40H Service Manual - Manual (Page 34)

SECTION 2 - PROCEDURES
2-14
– JLG Lift – 3120240
20. 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 2-2.)
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 lift cylinder in place using suitable slings or
supports, aligning 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 cylinder port plugs and hydraulic line caps
and correctly attach lines to 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 boom prop and overhead crane. Activate
hydraulic system.
6. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
7. Check fluid level of hydraulic tank and adjust as nec-
essary.
2.11 BOOM MAINTENANCE.
Removal.
1. Remove the platform from boom assembly.
2. Remove the slave leveling cylinder from boom
assembly.
NOTE: Boom Assembly weighs approximately:
Two Section Boom - 1795 lbs. (814 kg).
Three Section Boom - 2275 lbs. (1032 kg).
3. Using suitable lifting equipment, adequately support
boom weight along entire length of retracted boom.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-
ATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF
CONTAMINANTS INTO SYSTEM.
4. Tag and disconnect hydraulic lines that run along
the side of the boom.
5. Remove hardware attaching upper lift cylinder
attach pin to boom.
6. Using a slide hammer or similar tool, and taking care
not to damage pin, remove pin from boom.
7. Using all applicable safety precautions, and only if
necessary, operate crane and fully retract lift cylin-
der.
8. Shut down machine systems.
9. Tag and disconnect all wiring to ground control box.
10. Loosen and remove hardware securing boom pivot
pin.
11. Ensuring that boom is adequately supported and
using a suitable slide hammer, carefully remove
pivot pin from boom and turntable structure. Ensure
that boom and turntable structure are not damaged.
12. Carefully lift boom assembly clear of turntable and
lower to ground or suitably supported work surface.
Disassembly.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-
ATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF
CONTAMINANTS INTO SYSTEM.
1. Remove hydraulic lines, electrical cables, carrier
tube, power track from right side of boom assembly.
NOTE: Step (2) applies to 3 Section Boom Only.
2. Remove the telescope cylinder, extension chain
assembly