SkyTrak 8042 Service Manual - Manual (Page 512)

8.97 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
8.12.4 Shuttle Valve
The shuttle valve (2) is attached to the brake valve (3)
with a tee fitting (4). The shuttle valve joins the brake
valve load sense line (5), the shuttle IN line (6) from the
main control valve and the steering valve shuttle IN line
(7). The shuttle valve contains a pressure dependent,
two-way check and is a non-serviceable item. It must be
replaced in its entirety if defective.
a. Shuttle Valve Removal
1. Park the vehicle on a firm, level surface, fully retract
all hydraulic cylinders, ground the attachment (if
any), 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 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. To remove the shuttle valve (2), remove the right
front console panel on the front dash. Refer to
Section 4.5, “Cab Removal,” for information on
removing the dash panel.
5. Disconnect, label and cap all hydraulic fittings and
hoses during removal from the shuttle valve (2).
Disconnect the brake valve load sense line (5) and
pull the shuttle valve assembly forward. Disconnect
the shuttle IN line (6) and the steering valve shuttle
IN line (7). Wipe up any hydraulic fluid spillage.
b. Shuttle Valve Cleaning, Inspection and
Reassembly
1. Clean the shuttle valve with a suitable cleaner before
inspection.
2. Inspect internal passageways and the shuttle valve
overall for wear, damage, etc. If inner surfaces of the
component DO NOT display an ultra-smooth,
polished finish, or are damaged in any way, replace
the shuttle valve. Often, dirty hydraulic fluid causes
failure of internal seals and damage to the polished
surfaces within the shuttle valve.
3. Replace a defective shuttle valve with a new part.
MA7440
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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.