If your vehicle's brake master cylinder is going out, you'll likely notice a decrease in braking power. This can manifest as a longer stopping distance, increased pedal travel, or a spongy feel when pressing the pedal. In some cases, you may also see brake fluid leaking from the cylinder. If you experience any of these symptoms, it's important to have the cylinder checked by a qualified mechanic as soon as possible. Left unchecked, a failing brake master cylinder can lead to complete loss of braking power, increasing the risk of an accident.