The basic task of the coolant is to maintain the engine temperature at the right level and protect the cooling system against corrosion. The coolant circulates within the cooling system, preventing limescale and other material from settling in it. It also lubricates the water pump. Gradually, the coolant loses its properties, which may cause serious failures, including engine seizure or destruction of the engine block. The coolant should be changed every three years or every 60 thousand kilometres.