Case 721G Stage IV, Руководство оператора

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7 - MAINTENANCE
Hour meter
The hour meter enables service operations to be sched-
uled. Its hourly indications are the same as those of a
clock when the engine is running.
Servicing intervals are carefully calculated to guarantee
safe and efficient machine operation.
Be sure to carry out all the servicing operations properly
as defined in this manual.
Variable periodic maintenance
Some working environments require that maintenance be performed more frequently. Take into consideration dust,
dirt, moisture, extreme hot or cold and many other factors when servicing the machine. Certain equipment or auxiliary
tools may cause more stress on hydraulics, drivetrain, engines or filters. Perform the following maintenance on regular
schedules, but maintenance often needs special attention when conditions so require.
Engine air filter
Replace the primary element if the air filter indicator lamp
illuminates.
The primary element may be cleaned, however a new
element is recommended. The inner element cannot be
cleaned and must be replaced.
To clean the primary air filter, hold with the rubber seal
facing up. Tap all sides of the filter with your hand. Blow
the filter out with compressed air — maximum pressure
4.8 bar ( 70 psi ). Hold the nozzle a minimum of 7.6 cm
( 3 in ) away from filter. Use a nozzle diameter no smaller
than 6.4 mm ( 0.25 in ). Inspect the filter for damage.
Wipe the filter seal off and clean all dust from air cleaner
housing. Never use water to clean the primary filter.
Tires and wheels
Adjust the inflation pressure of the tires when circum-
stances require.
Keep the tires properly inflated and
check the torque of the wheel bolts/studs.
Check the wheels for proper torque every twenty hours
when new and until the wheels remain tight.
Air conditioning condenser
The air conditioning condenser is located in the cooling
box at the rear of the machine. Use compressed air to
remove debris and build up on the condenser.
Fuel cooler
The fuel cooler is located in the cooling box at the rear of
the machine. Use compressed air to remove debris and
build up that may impede proper function of the cooler.
Fuel pre-filter
Raise the engine hood and drain water and sediment from
the fuel pre-filter. Remove electrical connectors. Slowly
loosen the drain valve located under the pre-filter until
clean fuel runs out.
Retighten the valve and replace the electrical connectors.
Do not overtighten valve. This procedure should be a
periodic maintenance procedure dependent upon climate
and use conditions. See the complete procedure for the
fuel pre-filter and fuel filter in this section. Use the bleed
screw on the filter housing to release air from the fuel
system.
Priming the fuel system
Prolonged period of inactivity or running out of fuel may
allow air to get into the fuel system. If this should happen
make sure the tank is full and then prime the system using
the manual priming pump on the fuel pre-filter.
Fuses
Open the access panel located inside the cab, behind the
operator’s seat, to reach the fuses. If a fuse has blown
the indicator light will illuminate.
NOTE: if a fuse blows, replace the fuse at once. Locate
the problem and if it reoccurs, have it checked by a ser-
vice technician.
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