What Does Brake Fluid Do?
What is brake fluid and what does it do? Brake fluid is one of the most overlooked performance parts within a braking system. Whether you’re driving to work or enjoying a day on the track, the most important mechanical system in your car or powersport vehicle may be your brakes.
The chief purpose of brake fluid is to convert brake pedal pressure into stopping power while remaining stable in a variety of conditions. To illustrate, when the brake calipers (and the fluid reaching them) get hot, the fluid will often boil. The boiling process produces gas, which is more compressible than the fluid. Consequently, it leaves you with both a soft, spongy brake pedal feel and a longer travel time when applying the brakes. It can be a very unsettling feeling, not to mention unsafe.
Additionally, brake fluid is hygroscopic. In other words, it absorbs moisture from the atmosphere. This takes place over a period of time. When the fluid contains water, it starts to boil with less heat. Because brake rotors and brake calipers generate an exorbitant 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 because your brake system will not function properly.