Coolant is an essential element in the proper operation of an engine. It allows the engine to cool down and regulate its temperature. To keep an engine in good working order over time, it is important to check and test it regularly and, if necessary, replace it completely.
Visual coolant test
As a first step, a visual test can be carried out by checking its colour. Please note that the coolant does not fill all of these functions because of its normal colour appearance. After 2 years, the percentage of glycol decreases and the freezing and boiling points of the coolant drop.
In a second step, it is advisable to check the expansion tank for foam. Foaming corresponds to the introduction of air into the cooling circuit causing aeration of the liquid. This phenomenon amplifies the problem of cavitation erosion, especially on the water pump impeller.
Coolant pH Test
The coolant ph test provides information on the acidity of the coolant. Normally for a coolant in good working order it should be included in 7.5 and 7.
When the pH is below 7, the acidity of the liquid increases, leading to increased corrosion within the system. This is because an aging fluid will have a higher acidity level that will cause corrosion of cylinder liners, cylinder blocks, cylinder head, water hoses and hoses
Conversely, a pH above 7.5 is just as bad for the cooling system because there is a risk of damaging seals and softer metal components.
Liquid test using a refractometer
The refractometer is an instrument for measuring the freezing point of Glycol which is a basic element in the coolant. It uses 3 precise measurement scales.
The refractometer works on the principle that as the concentration of the solution increases, its refractive index changes proportionally. The measured refractive angle changes on the scale. The higher the concentration of ethylene glycol or propylene glycol, the lower the freezing point of the solution. The specific gravity measured at the center of the scale indicates the level of acidity of the coolant. Therefore, this instrument indicates whether the coolant is of good quality or needs to be replaced.