Komatsu D31EX-21, Operation & Maintenance Manual, Page: 185 / 256

MAINTENANCE
OUTLINE OF SERVICE
4-5
OUTLINE OF SERVICE 4
OUTLINE OF OIL, FUEL, COOLANT, AND PERFORMING OIL CLINIC 4
OIL 4
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Oil is used in the engine and hydraulic equipment under extremely severe conditions (high temperature, high
pressure), and deteriorates with the use.
Always use oil that matches the grade and maximum and minimum ambient temperatures recommended in
the Operation and Maintenance Manual. Even if the oil is not dirty, always change the oil after the specified
interval.
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Oil corresponds to blood in the human body, so always be careful when handling it to prevent any impurities
(water, metal particles, dirt, etc.) from getting in.
The majority of problems with machines are caused by the entry of such impurities.
Take particular care not to let any impurities get in when storing or adding oil.
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Never mix oils of different grades or brands.
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Always add the specified amount of oil.
Having too much oil or too little oil are both causes of problems.
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If the oil in the work equipment is not clear, there is probably water or air getting into the circuit. In such cases,
please contact your Komatsu distributor.
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When changing the oil, always replace the related filters at the same time.
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We recommend you have an analysis made of the oil periodically to check the condition of the machine. For
those who wish to use this service, please contact your Komatsu distributor.
FUEL 4
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After completing the day's operations, fill the fuel tank to force out any air containing moisture. This will pre-
vent the moisture from condensing and mixing with the fuel.
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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 in the Operation and Maintenance Manual.
Fuel may congeal depending on the temperature when it is used (particularly in low temperature below -15°C).
It is necessary to use the fuel that is suitable for the temperature.
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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.