According to the Karl Fisher testing method, fresh brake fluids contain an average of 0.1% moisture. However, the conductivity meters available in the market today give different readings, even if the same samples were retested. Adding moisture to samples also resulted in incorrect readings and different readings from different testing devices. In some cases, the addition of moisture did not even show up at all in the readings, whereas significant amounts of moisture (up to 6%) had been added to the brake fluid being tested.

We cannot always rely on off the shelf handy devices like the conductivity meters in particular, for instance the tester pens, hardly ever give a correct indication of the brake fluid’s condition. In theory, we would go as far as to say that blindly relying on the readings of the tester pen could be life-threatening if the brake fluid tester fails to detect an increase in moisture content. We recommend using a commercial boiling point test device as this method provides the most reliable results. At Euromotive we use the proper equipment to truly & accurately test your brake fluid.

In general, the boiling point of a brake fluid is seen as an important indicator when establishing its quality. Brake fluids with too low a boiling point can cause reduced braking performance, especially during hard or prolonged braking. The more moisture that is absorbed by a brake fluid, the lower its boiling point becomes. Brake fluids are hygroscopic, which means that they absorb moisture from the surrounding air.