- A special hydrometer, available as an aftermarket item or made available at petrol stations.
In advance, before the onset of the winter period, it is necessary to regularly check the concentration of the coolant, especially in cases where clean water is added.
- Warm up the engine until the radiator supply hose becomes warm.
- Open the lid of the expansion tank.
Suck in the coolant with the hydrometer and read the float readings. In the latitudes of Germany, frost resistance should be ensured down to -30°C, in regions with a very cold climate - up to -45°C.
Topping up antifreeze concentrate
In the latitudes of Germany, frost resistance down to -30°C must be ensured. To obtain the required ratios in the mixture, a certain amount of coolant must be drained or sucked out, and then the same amount of concentrate must be added.
Caution: Use only branded coolants based on ethylene glycol. The antifreeze concentrate must be compatible with aluminum parts of the cooling system.
Example: The result of the hydrometer measurement on a 1.3 l engine gave frost resistance up to -10°C. In this case, it is necessary to drain 1.5 l of coolant from the cooling system and add 1.5 l of pure concentrate. In this case, frost resistance will be -30°C.
- Close the expansion tank cap and, after a test drive, check the frost resistance again.