Antifreeze check (Audi A4 B5)

To check the frost resistance of the coolant, you need a hydrometer. It measures the specific gravity of the liquid. Due to the different addition of anti-corrosion agents, the specific gravity of individual types of antifreeze may be different. To make a completely accurate measurement, you need a hydrometer adjusted to the poured antifreeze. In case of doubt, subtract a tolerance of 2-3°C from the obtained value.

1. Suck out some coolant from the expansion tank, the hydrometer should float freely.

2. The hydrometer is immersed more or less deeply depending on the specific gravity of the liquid.

3. Use the scale to determine the temperature up to which the freeze protection is effective.

4. Some devices have arrows that can be used to determine frost resistance.

Antifreeze concentration regulation

Most often it turns out that the concentration of antifreeze is already insufficient. In this case, you need to add antifreeze; approximately 1/2 l per 10°C increase in freeze protection.

1. Remove the lower trim of the engine compartment (chapter Body parts).

2. Place the tray under the car.

3. When the engine is cold, disconnect the lower water hose from the radiator and drain 1 to 2 liters of coolant.

4. Reinstall the hose and tighten the screw gently.

5. Pour in the appropriate amount of undiluted antifreeze and top up together with the drained coolant.