The heart and soul of your car, truck or SUV's brake system is the brake master cylinder. Even though it looks a little like a blender bolted to your firewall, the brake master cylinder is in charge of maintaining the proper amount of pressure in your brake lines. Without a functioning brake master cylinder, you could stomp on the brake pedal, and it'll just sink right to the floor. When your stock brake master cylinder starts to show its age, pick up a low-cost replacement from AutoAnything and get free shipping.