What are the reasons for coolant overflow?

[OPaislee]

The reasons for coolant overflow are: 1. Part of the coolant position is occupied by air, and the expansion index of air is much higher than that of liquid; 2. The engine cooling system is blocked or has poor heat dissipation; 3. The external temperature is low, and the coolant will shrink below the min line. The functions of coolant are: 1. Prevent the liquid in the car radiator from freezing in winter, which may cause the radiator and engine cylinder block to crack; 2. Prevent corrosion of metal parts; 3. Prevent aging of rubber parts; 4. Reduce the generation of scale to avoid blocking the circulation pipeline and affecting the heat dissipation function of the cooling system. The method for replacing coolant is: 1. Unscrew the radiator cap, open the radiator drain valve, and drain the coolant; 2. After the cooling system is completely drained, close the radiator drain valve; 3. Add new coolant, cover and tighten the radiator cap and liquid storage tank cap.