JLG 660AJ Service Manual - Manual (Page 189)

SECTION 5 - HYDRAULICS
3121616 – JLG Lift – 5-9
Tower Boom Lift Cylinder Removal
Refer to Figure 5-6., Boom Positioning and Support, Cylinder
Repair.
1. Place machine on a flat and level surface. Place main
boom in a horizontal position with telescope cylinder
fully retracted. Place tower boom in a fully elevated and
fully retracted position.
2. Support main boom with a prop. Support upright with
an overhead crane.
3. Using slings restrain tower lift cylinder.
4. Remove mounting hardware securing cylinder rod pin
to tower boom. Drive out cylinder rod attach pin using a
suitable brass drift.
5. Tag, disconnect, and cap tower lift cylinder hydraulic
lines and ports.
6. Remove mounting hardware securing cylinder barrel
pin to turntable. Drive out cylinder barrel pin using a
suitable brass drift.
7. Carefully remove restraining slings. Remove tower lift
cylinder from turntable and place in a suitable work
area.
8. Fully retract lift cylinder. Use auxiliary power source if
necessary.
Figure 5-7. Tower Telescope Cylinder Removal
FLY PIN ACCESS
Base Ref.
Fly Ref.
Powertrack Hardware
Lower Cover Plate
Retaining Plates
OVERRIDE PLUNGER VALVE
Turntable Ref.
Lift Cylinder Ref.
Pry Bar
Plunger
Valve