Brake fluid is used in hydraulic braking systems to transport the pressure applied to the pedal to the brakes to stop the car. You should check the fluid in your brake fluid reservoir regularly to ensure that there is enough to stop air getting into the brake lines, making your braking less effective. This is especially important for emergency stops when you need full braking capacity. Our brake fluid range is quality assured, we have Dot 4 brake fluid, Dot 3 brake fluid and Dot 5.1 brake fluid too. If you're not sure which to choose for your vehicle consult the manual, give us a call or look it up in the Car Parts section of the website using your registration. It couldn't be simpler to maintain fast effective braking.