Your car should stop quietly and smoothly. If you hear a hissing noise every time you press the brake pedal, it’s a warning sign you shouldn’t ignore. In many cases, the sound points to a vacuum leak, a failing brake booster, or another issue affecting your braking system. While some hissing noises may be harmless, others can reduce braking performance and compromise your safety on the road. Knowing what causes this sound can help you avoid more expensive repairs and prevent dangerous brake failure. In this guide, we’ll explain the most common reasons your car makes a hissing noise when braking
