Lift cylinder removal, Lift cylinder removal -4, Machine positioned for cylinder removal -4 – JLG 9MP Service Manual User Manual
Page 48
SECTION 5 - MAST COMPONENTS
5-4
– JLG Lift –
3121163
5.3
HYDRAULIC LIFT CYLINDER -
REMOVAL, INSPECTION AND REBUILD
HYDRAULIC CYLINDERS ARE DESIGNED TO HOLD HYDRAULIC
FLUID UNDER HIGH PRESSURE. ENSURE ALL APPROPRIATE MEA-
SURES ARE TAKEN TO RELIEVE RESIDUAL PRESSURE IN THE CYL-
INDER BEFORE DISCONNECTING LINES.
Lift Cylinder Removal
Removal of the hydraulic lift cylinder without removing the
mast from the machine requires laying the machine on it’s
back (hood side) with the platform end on top.
1.
Remove the following components from the
machine before laying machine on it’s back:
• Rear Cover (See Section 4)
2.
Seal the vented cap on the hydraulic fluid reservoir
by removing the cap, covering the hole with a few
layers of plastic wrap or equivalent. Then install and
tighten the cap over the plastic wrap to prevent leak-
age of hydraulic oil from the reservoir while machine
is in a layed back position.
3.
Use a forklift truck or overhead crane and carefully
lay the machine on it’s back, place a support under
the mast end, keeping mast close to level. (See Fig-
ure 5-3.)
4.
At the base end, on the lift cylinder valve block,
remove and tightly cap the extend and return
hydraulic lines.
5.
At the top of the mast, remove the mini cover from
the top of the mast section 2 and the chain guard
from mast section 3.
6.
Manually extend the mast assembly until the top of
mast section-2 is extended approximately one (1)
foot (31cm), to allow access to the sheave wheel-
cylinder attach block at the top of mast section-2
and the lift cylinder.
1. Support Mast Here Under Ground Station Support Beam.
2. Use An Object Capable Of Supporting Machines Weight.
Figure 5-3. Machine Positioned for Cylinder
Removal.
1
2
Remove Hydraulic Extend and Return Lines
1. Cylinder Extend Line
2. Cylinder Return Line
Notes:
Cap lines tightly to keep lines clean and also to keep
hydraulic fluid from the pump/motor reservoir from
leaking out.
Extending Mast Sections
1. Mast Section-2
2. Extend 1 ft. (31cm) (Approx.)
1
2
1
2