Slave Cylinders - JLG sky trak mmv Service Manual

f. Attachment Tilt Cylinder Installation
1. Attach a suitable sling to an overhead crane or other
suitable device and to the attachment tilt cylinder at
the eyelet or hook. Make sure the device used can
actually support the cylinder. Place the attachment
tilt cylinder in position within the gooseneck. Refer to
Section 4.3, Boom Assembly Maintenance .
2. Install the lower attachment tilt cylinder pin by
tapping it out through the bottom of the quick attach
(if installed). Install the retaining bolt.
3. Coat the attachment tilt cylinder base pin with anti-
seize compound and install the pin by tapping it in
through the top of the gooseneck.
4. Secure the attachment tilt cylinder base pin to the
boom with two 2" external retaining rings.
5. Install the lower pivot pin and quick attach as required.
6. Connect the attachment tilt cylinder hydraulic hoses
in relation to the labels or markings made during
removal.
WARNING:
operation in closed areas with inadequate ven-
tilation. Failure to properly ventilate exhaust
fumes can result in death or serious injury.
7. Start the engine and run at approximately one-third to
one-half throttle for about one minute without moving the
vehicle or operating any hydraulic functions.
WARNING:
under pressure can penetrate the skin, causing
death or serious injury.
8. Inspect for leaks and check the level of the hydraulic
fluid in the reservoir. Add hydraulic fluid to the
reservoir as needed. Shut the engine OFF.
9. Wipe up any hydraulic fluid spillage in, on, near and
around the vehicle, work area and tools.
10. Conduct a pressure check of the attachment tilt
cylinder hydraulic circuit and bleed the circuit as
outlined in the procedure that follows.
g. Attachment Tilt Cylinder Pressure Checking and
Circuit Bleeding
1. Attach a 5000 psi (345 bar) gauge to the main
control valve at the extend/retract base port relief to
test the attachment tilt cylinder hydraulic system
circuit pressure. The unit is equipped with test
fittings from the factory. Pressure readings should be
4000 psi ±50 psi (276 ±3,4 bar). Refer to Section
9.7, Hydraulic System Testing .
Model MMV Rev. 12/04
Avoid prolonged engine
Escaping hydraulic fluid
2. With no accessory installed on the quick attach, start
with the lift/lower and attachment tilt cylinders fully
retracted.
3. Fully extend the attachment tilt cylinder. Hold the
attachment tilt joystick at full extend while fully
raising the lift/lower cylinder.
4. Fully retract the attachment tilt cylinder. Hold the
attachment tilt joystick at full retract while fully
retracting the lift/lower cylinder.
5. Repeat Steps 3-4 five times.
9.14.5

Slave Cylinders

Each slave cylinder (24) is secured to the vehicle frame
and outer boom with cylinder mount pins, capscrews and
nuts.
a. Slave Cylinder Removal
1. Park the vehicle on a firm, level surface, fully retract
all hydraulic cylinders, then raise the boom to
approximately a 30-degree angle. Support the
boom. Place the travel select lever in [N] NEUTRAL,
place the neutral lock lever in the [N] NEUTRAL
LOCK position, engage the park brake switch and
shut the engine OFF.
2. Place an Accident Prevention Tag on both the
ignition switch and the steering wheel, stating that
the vehicle should not be operated. Refer to Section
1.5, Accident Prevention Tag Usage .
WARNING:
cause severe burns. Wait for hydraulic fluid to
cool before servicing any hydraulic component.
3. Unlatch and open the engine cover. Allow the
hydraulic fluid to cool.
Hydraulic System
24
Hot hydraulic fluid can
MM3780
9.147