What are the effects of too much coolant?

[DeLouis]

There is no significant impact from overfilling the antifreeze. Excess antifreeze will expand due to heat during vehicle operation and overflow through the pressure relief valve, which is harmless. It may only leave some stains. It is advisable to use a syringe to remove any antifreeze above the MAX level. Typically, the coolant reservoir has MAX (maximum) and MIN (minimum) level markings, and the antifreeze should be filled between these two levels. Below are the functions of antifreeze: 1. Winter antifreeze protection: To prevent the coolant from freezing and causing the radiator or engine block to crack when the car is parked in winter, the freezing point of the coolant should be about 10°C lower than the lowest temperature in the region, preparing for sudden weather changes. 2. Anti-corrosion: The coolant should protect metal components from corrosion and prevent rubber parts from aging. 3. Anti-scaling: The coolant should minimize scale formation during circulation to avoid clogging the pipes and affecting the cooling system's heat dissipation function.