What is coolant?
Coolant is the common word for the liquid in the cooling system. Its primary function is to protect against freezing, rust and overheating, while at the same time lubricating the engine components with which it comes into contact. Its role is to absorb heat from the engine and dissipate it through the radiator.
The 4-season liquid is composed of water and antifreeze (glycol) with various additives (bitter substances, silicate, antioxidants, foaming) and colored. Silicates form a protective layer on metal surfaces and prevent limestone deposits. Antioxidant agents prevent corrosion of components. Anti-foaming repels the foaming of the cooling liquid. The glycol retains flexibility in hoses and joints and increases the boiling point of the coolant.
An essential operation for the longevity of the engine
The coolant is used to cool the engine but also to protect it from internal corrosion, to lubricate the circuit (especially the water pump) and of course to withstand very low temperatures. As it ages, the liquid loses its qualities.
Coolant replacement is an operation that must be carried out on all vehicles every 2 to 4 years, depending on the manufacturer.
After 2 years, the coolant loses its properties and benefits. It is not because it looks normal in terms of colour that the coolant still contains all its functionality.
- Over time, the percentage of glycol in the coolant decreases, resulting in a decrease in freezing and boiling points of the liquid.
- The PH rate also decreases, resulting in increased acidity and corrosion in the cooling system, leading to a more rapid deterioration of durites, water pumps and all organs in contact with the cooling system.
When should the coolant be replaced?
The coolant oxidizes and degrades over time as it becomes loaded with waste. It becomes fouled and may change colour. It loses its cooling efficiency and freeze protection. The coolant becomes acidic and can damage seals or engine cooling components.
Therefore, it is recommended that coolant be replaced every 2 to 4 years, as recommended by the manufacturers.
It is important to check the condition of the liquid about every 6,200 miles (10,000 km).
Fluid replacement and fluid leveling is done when the engine is cold. Low-temperature liquids (-25°c or even -35°c) that are more resistant to frost are to be preferred.