SkyTrak 8042 Service Manual - Manual (Page 538)

8.123 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
3. Use new oiled o-rings, and reattach and secure the
hydraulic hoses to the slave cylinder fittings.
4. Start and run the engine at approximately one-third
to one-half throttle for about one minute, without
moving the vehicle or operating any hydraulic
functions.
5. Inspect for leaks and check the level of the hydraulic
fluid in the reservoir. Shut the engine OFF. Add
hydraulic fluid if required.
6. Conduct a pressure check of the attachment tilt/
slave cylinder hydraulic circuit, and bleed the circuit
as outlined in the procedure that follows.
7. Wipe up any hydraulic fluid spillage in, on, near and
around the vehicle, work area and tools.
g. Slave Cylinder Pressure Checking and Circuit
Bleeding
1. Attach a 4000 psi (276 bar) gauge to the test fitting
on the main control valve to test the system
pressure. Pressure readings should be
3000 ±100
psi (207 ±7 bar). Refer to Section 8.7, “Hydraulic
System Testing.” To check each cylinder pressure,
consult the factory.
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. Monitor
pressure while fully raising the lift/lower cylinder.
4. Fully retract the attachment tilt cylinder. Monitor
pressure while fully retracting the lift/lower cylinder.
5. Repeat Steps 3 and 4 five times.
8.13.6 Extend/Retract Cylinder
The extend/retract cylinder (21) is located under the
boom, attached to the rear of the outer boom and the front
of the intermediate boom.
a. Extend/Retract Cylinder Removal
1. Park the vehicle on a firm, level surface, and fully
retract all hydraulic cylinders. 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. Support the
boom in a horizontal and level position with blocking.
2. Place an Accident Prevention Tag on both the
ignition key switch and the steering wheel, stating
that the vehicle should not be operated. Refer to
Section 1.5, “Accident Prevention Tags.”
3. Unlock and open the rear door. Allow the hydraulic
fluid to cool.
4. Operate the hydraulic controls after the engine has
stopped, to relieve any trapped pressure.
5. Label or otherwise mark the hydraulic hoses in
relation to the extend/retract cylinder. Disconnect
and cap both hoses and the cylinder fittings.
WARNING:
Avoid prolonged engine
operation in closed areas with inadequate
ventilation. Failure to properly ventilate exhaust
fumes can result in death or serious injury.
WARNING:
Escaping hydraulic fluid
under pressure can penetrate the skin, causing
death or serious injury.
WARNING:
Hot hydraulic fluid can
cause severe burns. Wait for hydraulic fluid to
cool before servicing any hydraulic component.
WARNING:
Escaping hydraulic fluid
under pressure can penetrate the skin, causing
death or serious injury. Relieve hydraulic
pressure before servicing any hydraulic
component.
MH3690
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