Service Manual Instruction Manual

SECTION 5 - HYDRAULICS
3121616 – JLG Lift – 5-7
Main Boom Lift Cylinder Removal
1. Place machine on flat and level surface. Start engine and
place main boom horizontal. Shut down engine and
prop boom. (See Figure 5-1., Boom Positioning and Sup-
port, Cylinder Repair.
2. Remove bolt and keeper pin from cylinder rod pin (7).
Drive out pin using a suitable brass drift.
3. Fully retract lift cylinder rod using auxiliary power,
4. Disconnect, cap, and tag main boom lift cylinder (8)
hydraulic lines and ports.
5. Remove barrel end attach pin (9) keeper pin and bolt.
Drive out barrel end attach pin from upright using a suit-
able brass drift.
6. Remove cylinder from boom and place in a suitable
work area.
Main Boom Lift Cylinder Installation
1. Install lift cylinder in place using suitable slings or sup-
ports. Align attach pin mounting holes on upright.
2. Using a suitable drift, drive barrel end attach pin (3)
through mounting holes in lift cylinder and upright.
Install keeper pin and bolt.
3. Remove cylinder port plugs and hydraulic line caps.
Connect previously tagged lines to cylinder ports.
4. Using auxiliary power extend cylinder rod until attach
pin hole aligns with those in the boom. Using a suitable
drift drive cylinder rod attach pin (2) through aligned
holes, taking care to align the grooved pin holes. Install
keeper pin and bolt.
5. Remove boom prop and overhead crane. Activate
hydraulic system.
6. Using all applicable safety precautions, operate boom
functions. Check for correct operation and hydraulic
leaks. Secure as necessary.
7. Check fluid level of hydraulic tank. Adjust as needed.
Figure 5-4. Leveling Cylinder Removal
1
2
3