Safety when servicing
Service position 147
7 Install chocks at the front and rear tandem wheels. Wedge the
chocks in place.
8 Fasten a ‘DO NOT OPERATE’ or similar warning tag on the
steering wheel.
9 Turn the battery isolation switch OFF to the (O) position.
10 Allow the engine and hydraulic system to cool before working
in these areas.
11 Be aware of other service personnel in your work area.
If the service procedure includes welding, refer to Welding
and electronic components page 150.
If the service procedure includes repair to the hydraulic sys-
tem, you must perform the following steps.
All of the hydraulic implements except the moldboard slide have a
lock valve between the main control valve and the cylinder.
Moving the main control valve levers will not relieve any pressure
that is trapped in the cylinder(s). The only exception is the mold-
board slide, which does not have a lock valve in the circuit.
n Carefully loosen the appropriate hydraulic line to allow any
trapped oil under pressure to be relieved.
n Connect blade lift accumulators (if installed) to their hydraulic
circuits by turning the shut-off handles counterclockwise.
n Relieve residual hydraulic pressure in moldboard slide circuit
by operating the control lever.
n Some circuits have electrically activated float valves. To re-
lieve pressure in these circuits, turn on the ignition key without
starting the engine and place the control lever in the float de-
tent position.
For more information on relieving trapped pressure in the hy-
draulic system, refer to the Service Manual.
WARNING!
• Fluid escaping under pressure can penetrate the skin
causing serious injury. Do not use your hand to check
for hydraulic leaks. Use a piece of cardboard. If
possible, relieve all pressure before disconnecting
hoses.
• Make sure all personnel are clear of moldboard,
attachments or components controlled by the hydraulic
circuits. Unexpected movement of the component could
result in severe personal injury or death.
• Be careful to place the machine in a position that does
not allow any external load on the cylinder(s) or
circuit(s) to be worked on.
• Properly block the machine or implement to prevent
movement. Relieving trapped pressure by loosening a
fitting may allow the machine or implement to move
unexpectedly.
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