Komatsu PC118MR-8, Operation And Maintenance Manual

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MAINTENANCE PROCEDURES
MAINTENANCE
4-80
CLEANING OF THE COOLING SYSTEM AND CHANGING THE COOLANT 4
WARNING
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The coolant temperature and pressure inside the radiator are very high immediately after turning off
the engine. There is a risk of fire if the cap is removed to drain the coolant. Allow the coolant to cool,
turn the cap slowly to relieve pressure and unscrew it completely.
q
Washing is performed with the engine running. Move the lever of the safety device to the LOCK
position (L) when leaving the operator's seat. (See "MAINTENANCE WITH ENGINE RUNNING (2-52)").
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For more details on starting the engine, see "BEFORE STARTING THE ENGINE (3-109)" and "Starting
the engine (3-130)".
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Washing is done with the engine running, so it is dangerous if the machine is moving and any one is
standing behind it. Never stand behind the machine when the engine is running.
Stop the machine on level ground when cleaning the cooling system or replacing the coolant.
Flush the cooling system and replace the coolant following the instructions in the following table.
The coolant has the important function of preventing both corrosion and freezing.
Komatsu machines are supplied with Supercoolant Komatsu (AF-NAC). The Supercoolant Komatsu (AF-NAC)
has high anticorrosion, antifreeze and coolant properties, so it can be used regularly for 2 years or 2000 hours.
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As a general rule, we do not recommend the use of refrigerants different than Supercoolant Komatsu (AF-NAC). If
another coolant is used, you may experience problems such as corrosion of the engine and the aluminium
components of the cooling system.
To maintain the anticorrosive properties of the Supercoolant (AF-NAC), keep the density of the fluid between 30%
and 68%.
Supercoolant fluid (AF-NAC) has already been diluted with distilled water. During use, check the previous
minimum temperatures and determine the density of the coolant using the following table.
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To determine the density, it is appropriate to estimate a temperature of about 10° C lower.
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The density of the coolant varies depending on the ambient temperature, but must always be kept to a minimum of
30%.
Coolant density table
Antifreeze Coolant Cleaning and replacement interval of the coolant
Supercoolant Komatsu (AF-NAC) Every 2 years or every 2000 hours, whichever occurs first.
Minimum temperature °C Over -10 -15 -20 -25 -30 -35 -40 -45 -50
Concentration (%) 30 36 41 46 50 54 58 61 64
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