Bosch Brake fluid is one of the most important components in a braking system. It transfers the braking force from the brake master cylinder to the wheel brakes. Additionally, it lubricates the moving parts and protects the entire system from corrosion. Brake fluids are also suitable for use in clutch systems. To do all this efficiently, the brake fluid must have a constant viscosity and boiling point that allow it to function under all temperatures and operating conditions.