When new, the brake fluid in your car is able to handle the very high temperatures normally seen in the brake calipers in heavy braking conditions. DOT5.1 brake fluid is hygroscopic in nature, meaning it absorbs water. Over time, the additional moisture that is absorbed by the fluid lowers the boiling point of your brake fluid. This dilution increases the likelihood of the brake fluid vapourizing within the brake lines during braking. Unlike fluid, gas is not compressible. So if your brake fluid vapourizes while you’re braking, you will be unable to stop the car.

In addition to this, the water in the hydraulic system will cause the delicate components to corrode, leading to very expensive repairs.

For these reasons, it is strongly recommended that you flush your brake fluid every 2 years.

This 500mL container of Motul DOT 5.1 brake fluid has a dry boiling point of 516°F/272°C, and a minimum wet boiling point of 365°F/185°C.

DOT5.1 grade brake fluids are glycol-based, and can be interchanged with DOT3 and DOT4 fluids.

NOTE: brake fluid will damage paint, so be careful not to get any on your car. If you do, rinse it off immediately.