Komatsu PC450-8 Operation & Maintenance Manual page 271

MAINTENANCE
FUEL
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To prevent the moisture in the air from condensing and forming water inside the fuel tank, always fill the fuel
tank after completing the day's work.
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The fuel pump is a precision instrument, and if fuel containing water or dirt is used, it cannot work properly.
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Be extremely careful not to let impurities get in when storing or adding fuel.
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Always use the fuel specified for the temperature in the Operation and Maintenance Manual.
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If the fuel is used at temperatures lower than the specified temperature (particularly at temperatures below
-15°C, the fuel will solidify.
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If the fuel is used at temperatures higher than the specified temperature, the viscosity will drop, and this
may result in problems such as a drop in output.
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Before starting the engine, or when 10 minutes have passed after adding fuel, drain the sediment and water
from the fuel tank.
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If the engine runs out of fuel, or if the filters have been replaced, it is necessary to bleed the air from the circuit.
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If there is any foreign material in the fuel tank, wash the tank and fuel system.
NOTICE
Always use diesel oil for the fuel.
To ensure good fuel consumption characteristics and exhaust gas characteristics, the engine mounted on
this machine uses an electronically controlled high-pressure fuel injection device. This device requires
high precision parts and lubrication, so if low viscosity fuel with low lubricating ability is used, the durabil-
ity may drop markedly.
COOLANT AND WATER FOR DILUTION
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The coolant has the important function of preventing corrosion as well as preventing freezing.
Even in the areas where freezing is not an issue, the use of antifreeze coolant is essential.
Komatsu machines are supplied with Komatsu Supercoolant (AF-NAC). Komatsu Supercoolant (AF-NAC) has
excellent anticorrosion, antifreeze and cooling properties and can be used continuously for 2 years or 4000
hours.
Komatsu Supercoolant (AF-NAC) is strongly recommended wherever available.
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When using Komatsu Supercoolant (AF-NAC), there is no need to use a corrosion resistor. For details, see
"CLEAN INSIDE OF COOLING SYSTEM (4-27)".
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When diluting the antifreeze coolant, use distilled water or tap water (soft water).
Natural water, such as a river water or well water (hard water), contains large amounts of minerals (calcium,
magnesium, etc.), and this makes it easier for scale to form inside the engine or radiator. Once scale is depos-
ited inside the engine or radiator, it is extremely difficult to remove. It also causes overheating due to poor heat
exchange, so when you dilute the coolant, we recommend that you use water with an overall hardness of less
than 100 PPM.
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When using antifreeze, always observe the precautions given in the Operation and Maintenance Manual.
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Antifreeze coolant is flammable, so be sure to keep it away from flame.
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The ratio of Supercoolant (AF-NAC) to water differs according to the ambient temperature.
For details of the ratio when mixing, see "CLEAN INSIDE OF COOLING SYSTEM (4-27)".
Supercoolant (AF-NAC) may be supplied in premix. In this case, never add diluting water.
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If the engine overheats, wait for the engine to cool before adding coolant.
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If the coolant level is low, it will cause overheating, and will also cause problems with corrosion due to air
entering the coolant.
OUTLINE OF SERVICE
4
4
4-5