Whether driving to work or enjoying a track day, the most important mechanical system in your car or powersports vehicle may be your brakes. Within the braking system, one of the most often overlooked performance parts is the brake fluid.
The purpose of brake fluid is to convert brake pedal pressure into stopping power while remaining stable in a variety of conditions. When the brake calipers (and the brake fluid reaching them) get hot, the fluid will often boil. The process of boiling produces gas which is more compressible than the brake fluid leading to a soft, spongy brake pedal feel and a longer travel time when applying the brakes. Over time, hygroscopic brake fluid begins absorbing water from the atmosphere.
Brake fluid containing water boils with less heat. Because brake rotors and brake calipers generate a high amount of heat, brake fluid must have a high heat tolerance — otherwise, the fluid would simply vaporize inside your brake lines and create a dangerous situation as your brake system will not function properly.