Generally, high-quality automotive antifreeze should be replaced once a year, while vehicles with shorter operating times can have it replaced every two years or every 30,000 kilometers. More details about antifreeze are as follows: 1. For Mercedes-Benz A-Class, B-Class, and C-Class, the antifreeze (coolant) replacement cycle is 40,000 kilometers or two years, while other models primarily require replacement every 60,000 kilometers or three years. The Mercedes-Benz Smart antifreeze replacement cycle is four years or 100,000 kilometers. 2. Antifreeze (coolant) replacement method: There is a drain valve at the bottom rear of the car's radiator, usually black. Loosening it will allow the radiator fluid to drain out. Never remove the drain valve when the engine is hot, as high-pressure engine antifreeze may spray out from the valve, potentially causing severe burns. Additionally, the antifreeze cap or radiator cap must be opened. Wrap a thick cloth around the radiator cap and slowly turn it a quarter turn to release accumulated pressure before fully unscrewing it. Never remove the radiator cap when the engine is hot. Drain the old antifreeze, then flush the fluid channels with clean water. Add clean water to the antifreeze reservoir and continue filling until the water flowing out becomes clear. Initially, the water flowing out may have a faint pink tint. Keep adding clean water until the outflow is clear. Start the engine and let it idle for 3 to 5 minutes to circulate the water.
