Komatsu D37EX-24 Operation & Maintenance Manual page 294

MAINTENANCE PROCEDURE
Coolant
Non-Amine Engine Coolant (AF-NAC)
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 coolant, investigate the
lowest temperature in the past and decide the density for the coolant from the following coolant density table.
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 over 30 % at least.
Coolant density table
Min. atmospheric tem-
perature
Density (%)
• 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. (For dilution
water, see "COOLANT AND WATER FOR DILUTION (4-6)".)
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 drained coolant.
1.
Place the machine on a level place.
2.
Stop the engine.
3.
Turn the radiator cap (1) slowly until it hits the stopper and
release the pressure.
4.
While pushing the radiator cap (1), turn it until it touches to
the stopper, then remove it.
4-18
°C Min. -10 -15
30 36
k k
WARNING
Cleaning of inside of cooling system and replacement of coolant
Every 2 years or every 4000 hours whichever comes sooner
-20 -25 -30
41 46 50
MAINTENANCE
-35 -40 -45
54 58 61
-50
64