Necessary details (consumables): Concentrate (antifreeze) for making coolant. For Ford and Mazda vehicles, Motorcraft Super Plus4 antifreeze or another one that meets Ford ESDM-97B49-A standards is used. Before the onset of cold weather, it is necessary to check the concentration of the coolant, especially in cases where water was poured into the system.
The engine should not be warmed up. Measurements are taken at room temperature, i.e. +21°C. There are hydrometers with a built-in thermometer.
Unscrew the expansion tank cap.
Fill the coolant into a hydrometer and determine the coolant density. It is often given simply in degrees, corresponding to the freezing point of the coolant. At a 1:1 ratio of concentrate to water, the freezing point is about -35°C.