JLG sky trak mmv Service Manual page 464

Hydraulic System
21
3
22
6
b. Stabilizer Cylinder Disassembly
Note: An additional o-ring may be included at the base
of the cylinder rod. This additional o-ring may be dis-
carded, as it served only in a temporarily protective role.
1. Clean the stabilizer cylinder (1) with a suitable
cleaner. Remove all dirt, debris and grease from the
cylinder.
IMPORTANT: Avoid using excess force when clamping
the cylinder in a vise. Apply only enough force to hold the
cylinder securely. Excessive force can damage the cylin-
der tube (6).
2. Secure the stabilizer cylinder (1) in a soft-jawed vise
or other holding device, and place a suitable
container beneath the cylinder to catch hydraulic
fluid run-off.
WARNING:
may be trapped inside the cylinder. Exercise
caution when removing a counterbalance valve
or a pilot-operated check valve from a cylinder.
Escaping hydraulic fluid under pressure can
penetrate the skin, causing death or serious
injury.
9.166
1
12
9
20
8
3
Significant pressure
5
2
15
14
13
17
10
18
11
3. Slowly remove the two pilot-operated check valves (3),
the pressure reducing valve (20) and the five
solenoid valves (21 and 22) on the manifold block (2)
if replacement of any of these components is
required. Label the solenoid valves with the locations
stamped on the manifold. Remove the solenoid
cartridges from the manifold.
Note: The head gland (5) is installed at a torque of
300-400 lb/ft (407-542 Nm). Use suitable tools to remove
the head gland.
4. Use a pin spanner wrench to unthread the head
gland (5) from the tube (6). The head gland is
installed at a torque of 300-400 lb/ft (407-542 Nm),
so a considerable amount of force is required to
remove it. Carefully slide the head gland down along
the rod toward the eyelet end, away from the cylinder
tube.
IMPORTANT: Protect the finish on the rod at all times.
Damage to the rod can cause premature seal failure.
5. Remove the locking insert (4) from its hole in the
head gland threads. Pry or drill out the insert as
required. DO NOT damage the head gland threads. A
new locking insert will be required for reassembly.
16
23
4
24
19
Model MMV Rev. 12/04
7
MM3830