Warning: You can be injured by hot coolant. Never open the radiator cap when the engine is hot, let it cool down.
When removing the radiator cap, be careful to avoid contact with pressurized water or steam. Place a cloth on top of the cap and turn the cap slightly counterclockwise to release the pressure. Then slowly unscrew the radiator cap.
1. Remove the radiator cap, radiator drain plugs and engine crankcase drain plugs to drain the coolant.
2. Remove the expansion tank and drain the liquid from it.
3. After the fluid has completely drained, reinstall the plugs and flush the cooling system with radiator cleaning fluid.
4. After completing the flush, completely drain the cleaning liquid and replace the plugs.
5. Select the desired concentration of coolant. Fill the cooling system with high-quality antifreeze - ethylene glycol of the selected concentration (50% antifreeze and 50% water, freezing point -36°C). Replace the radiator cap.
6. After the engine has been running for some time, check the coolant level and top up if necessary.
7. It is also necessary to pour coolant into the expansion tank so that its level is between the "FULL" and "LOW" marks.
(The material is republished from the web portal: www.hyundaibook.ru)
Note: Do not pour liquid into the expansion tank.