Corrosion and contamination of the intricate and expensive ABS and DSC hardware is to be absolutely avoided. Another factor is the elevated operating temperatures encountered in the high-performance braking systems BMW’s and other manufactures use, which makes maintaining a high boiling point critical to safety. A third reason is that brake fluid is hydroscopic. This means that it can absorb water, even directly out of the air. When water gets into your brake system, the brake fluid can not function properly, leading to poor braking or even complete brake failure