Why is the antifreeze flowing out from the overflow tank?

[RobertFitz]

Antifreeze flowing out from the overflow tank is mainly caused by the following reasons: 1. Check if the tank cap is damaged. High temperature inside the tank can cause antifreeze to leak out if the cap is damaged. 2. Overfilling of antifreeze. If the antifreeze level exceeds the marked line on the tank, it may overflow during driving. No overflow will occur if the antifreeze level is appropriate. 3. Thermostat failure. A faulty thermostat can cause the water temperature to rise too high. When the water temperature is too high, the coolant cannot enter the engine water passage for major circulation, leading to minor circulation in the radiator and resulting in antifreeze overflow.