What is the primary function of brake fluid?

The primary function of brake fluid is to create pressure in the brake lines. This hydraulic fluid is essential for the operation of the braking system in vehicles. When the driver presses the brake pedal, the brake fluid transmits force from the pedal to the brake components, allowing the brakes to engage effectively. This pressure is crucial for the proper functioning of disc or drum brakes, as it enables the brake calipers or wheel cylinders to clamp down on the brake rotors or drums, thus slowing down or stopping the vehicle.

While brake fluid may have some secondary roles, such as preventing corrosion and ensuring the system remains operational under high temperatures, its primary and most critical function is to facilitate the hydraulic action necessary for braking. This allows for consistent and efficient braking performance, which is vital for vehicle safety.