Radiator coolant how to replace it correctly

Radiator coolant how to replace it correctly


To keep your car in top condition, regular maintenance is essential. Among the various operations is the control of the coolant here’s what it is for and how to replace it.


The routine maintenance to be carried out on your car also includes checking the coolant, also called radiator fluid.

When we talk about engine coolant we mean a mixture of water and glycol that is introduced into the system when the thermostatic valve trips, and thus avoids overheating, or when the ambient temperature is particularly low.
Its function is essential as it protects the engine from overheating, preventing it from reaching too high temperatures.

The car coolant therefore has the function of cooling the gears and fluidizing their operation.

Thanks to its composition, the coolant absorbs the heat generated by the engine keeping it as much as possible at an ideal operating temperature to avoid overheating or even worse, melting.
Once the engine heat has been absorbed, the coolant reaches the radiator, where it is cooled by the fan, and then returns to contact with the engine again, continuing to perform its important task.
The function of the radiator fluid is also to act as antifreeze in order to make the areas subject to erosion more fluid.
Furthermore, its particular composition avoids the formation of rust and for this reason on modern cars it is not recommended to top up with simple water.In fact, even in winter, the engine tends to overheat. If the coolant turns to ice it can no longer perform this task and the engine could be damaged.


To understand if the radiator fluid needs to be topped up, just check the level of the fluid present.
Before doing this, make sure that the car is stationary on a level surface and that the engine is completely cold.
Once the hood has been raised, simply locate the coolant reservoir and check that the amount of liquid is between the minimum and maximum level.
If the liquid level is below the bottom mark, it will be necessary to add the liquid to no more than the maximum mark.


There are different types of coolant on the market, which differ in their composition and are recognizable thanks to the different colors.
The coolants are all colored to help locate any leaks and distinguish which products should not be mixed with each other.
In addition to being composed of water and glycol, the coolant contains specific inhibitors, which differ in the various colors.
A color has been associated with each type of inhibitor and therefore radiator fluids of the same color are compatible with each other.
To replace the radiator fluid, always keep the color of the existing fluid (blue, red, yellow or purple) and never mix liquids of different colors.
Liquids of the same color, despite being of different brands, are compatible with each other. You will find the type of liquid required by your car manufacturer in the use and maintenance booklet.
By mixing liquids of different colors, the fluidifying and anti-corrosion agents could create a reaction producing a gelatinous compound, which would clog the car circuit.