Komatsu PC220LC -8 Operation & Maintenance Manual page 290

MAINTENANCE
1. Stop the machine on level ground, then stop the engine.
2. Open engine hood (1).
3. Check that the cooling water temperature has gone down
enough to make it possible to touch the radiator cap surface by
hand, then turn radiator cap (2) slowly until it contacts the
stopper to release the pressure.
4. Following this, push radiator cap (2), turn it until it contacts the
stopper, then remove it.
5. Remove the undercover, then set the container under drain
valve (3) to catch the coolant mixture.
Open drain valve (3) at the bottom of the radiator and drain the
coolant.
6. After draining the coolant, close drain valve (3), and fill with city
water. When the radiator is full, start the engine and run at low
idling to raise the temperature to at least 90°C (194°F), then
continue to run for approx. 10 minutes.
7. Stop the engine and open drain valve (3) to drain the water.
8. After draining the water, clean the radiator with detergent.
For the cleaning method, follow the instruction of detergent.
9. Close drain valve (3).
10. Install the undercover.
11. Add Supercoolant through the water filler up to the bottom of
the filler port.
For details of the Supercoolant density, see the COOLANT
DENSITY TABLE.
12. Run the engine at low idling for 5 minutes to remove the air
from the water, then run at high idling for 5 minutes. (Leave
radiator cap (2) removed when doing this.)
MAINTENANCE PROCEDURE
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