Brake fluid is an important hydraulic component that applies pressure to the braking system. When the brake pedal is pressed, brake fluid transfers the force of the pedal into pressure that is applied to the brake pad to slow the car down.
Overtime moisture can build up in the brake fluid that will increase the corrosion of the copper lining in the brakes. It will also lower the boiling point of the brake fluid that means the liquid will vaporise rather than work as a liquid.
A brake fluid change will first test the levels of moisture in the brake fluid before flushing and replacing old brake fluids. Manufacturers recommend that you change your brake fluid every two years to maintain the performance of your car's braking system.