Is It Necessary to Upgrade Your Brakes? I believe upgrading your brakes is a must and should be one of the first modifications you make when increasing the power level of your vehicle. How Do Brakes Work? – Braking System 101 Hydraulic Action Your brake pedal is mechanically connected—usually through a metal rod—to a device called the master cylinder. The master cylinder is a sealed chamber filled with brake fluid, a specialized hydraulic fluid. Brake lines connect the master cylinder to your vehicle's brake calipers, allowing the fluid to travel throughout the braking system. When you press the brake pedal, the metal rod attached to it pushes a piston inside the master cylinder. This piston compresses the brake fluid, building pressure within the braking system. That pressure is transmitted through the brake lines and provides the force needed to operate the vehicle's brakes. More pedal force creates more hydraulic pressure, which translates into greater stopping power. When y...