Komatsu D51EX-24, Operation & Maintenance Manual

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METHOD FOR CLEANING INSIDE OF COOLING SYSTEM
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WARNING
• Immediately after the engine is stopped, the coolant is still hot and the pressure is accumulated in
the radiator. If the cap is removed under this condition and the coolant is drained, it may cause a
burn. Wait for the temperature to go down, and then turn the cap slowly to release the pressure.
• Start the engine and clean it. When standing up or leaving the operator's seat, lock the parking
brake lever and work equipment lock lever.
• It is very dangerous to go under the machine for cleaning while the engine is running, since the ma-
chine may move unexpectedly. While the engine is running, never go under the machine.
Place the machine on a level ground when cleaning or changing the coolant.
For cleaning the inside of the cooling system and changing the coolant, see the following table.
Coolant Cleaning of inside of cooling system and replacement of coolant
Non-Amine Engine Coolant (AF-NAC) Every 2 years or 4000 hours, whichever comes sooner
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 coolant is essential.
Komatsu machines are supplied with Non-Amine Engine Coolant (AF-NAC). Non-Amine Engine Coolant (AF-
NAC) has excellent anti-corrosion, antifreeze and cooling properties and can be used continuously for 2 years
or 4000 hours.
Komatsu recommends the use of Non-Amine Engine Coolant (AF-NAC). If you use another coolant, it may
cause serious problems, such as corrosion of the engine and aluminum parts of the cooling system.
To maintain the anti-corrosion properties of Non-Amine Engine Coolant (AF-NAC), always keep the density of
Non-Amine Engine Coolant between 30 % and 64 %.
Non-Amine Engine Coolant (AF-NAC) is already diluted with distilled water. When using the coolant, investigate
the lowest temperature in the past and decide the density for the coolant from the following coolant density ta-
ble.
When deciding the density for the coolant, set it for a temperature 10 °C below the actual lowest temperature in
the working area.
The coolant density varies according to the ambient temperature, but it must be 30 % or more.
Coolant density table
Min. atmospheric tem-
perature
°C
-10 or
more
-15 -20 -25 -30 -35 -40 -45 -50
Density (%) 30 36 41 46 50 54 58 61 64
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WARNING
• Coolant is toxic. When opening the drain valve, be careful not to get coolant on you. If it gets in
your eyes, flush your eyes with large amount of fresh water and see a doctor immediately.
• When handling the cooling water containing coolant that has been drained during changing the
coolant or repairing the radiator, contact your Komatsu distributor or request a qualified company
to perform the operation. Coolant is toxic, so never pour it into drainage ditches or drain it onto the
ground surface.
Non-Amine Engine Coolant (AF-NAC) is already diluted with distilled water, so it is not flammable.
Check the density with a coolant tester.
Prepare a hose to fill with coolant and water.
Prepare a container whose capacity is larger than the specified coolant volume to catch the drained coolant.
MAINTENANCE PROCEDURE MAINTENANCE
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