Komatsu PC2000-8 BACKHOE, Operation & Maintenance Manual

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MAINTENANCE
MAINTENANCE PROCEDURE
4-27
CLEAN INSIDE OF COOLING SYSTEM 4
WARNING
q
Immediately after the engine is stopped, the coolant is at high temperature. In addition, the radiator is
under high internal pressure. If the cap is opened under these conditions, it will cause burns. Wait for
the temperature to go down, then open the cap slowly to release the pressure.
q
When cleaning the cooling system with the engine running, set the lock lever to the LOCK position to
prevent the machine from moving.
q
For details of the procedure for starting the engine, see “BEFORE STARTING ENGINE (3-158)“ and
“STARTING ENGINE (3-189)“.
Stop the machine on level ground when cleaning or changing the coolant.
Clean the inside of the cooling system, change the coolant according to the table below.
Komatsu genuine Supercoolant (AF-NAC) 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 Supercoolant (AF-NAC). Supercoolant (AF-NAC) has excellent anticorrosion, anti-
freeze and cooling properties and can be used continuously for two years or 4000 hours. As a basic rule, we do
not recommend the use of any coolant other than Supercoolant (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 anticorrosion properties of coolant, always keep the density of coolant between 30% and 68%.
When selecting coolant, investigate the lowest temperature in the past and decide the density for the coolant from
the coolant density table below. When actually deciding the density for the coolant, set it about 10°C below lowest
temperature. The density must be over 30% at least. If the density of obtained coolant is higher than the necessary
density for lowest temperature, dilute it with adequate distilled water, and then fill it into the tank.
If there is any unclear point, please contact your Komatsu distributor.
Coolant density table
Coolant
Interval for cleaning inside of cooling system and
changing antifreeze coolant
Komatsu genuine supercoolant
(AF-NAC)
Every two years or every 4000 hours whichever
comes first
Minimum Temp
°C Above -10 -15 -20 -25 -30 -35 -40 -45 -50
°F Above 14 5 -4 -13 -22 -31 -40 -49 -58
Concentration (%) 30 36 41 46 50 54 58 61 64