The hissing sound and the hard brakes are likely related. Under the dash of your car, near the brake pedal, is a vacuum booster that helps you press the brake pedal. When you press the brake pedal, the booster uses engine vacuum to multiply your force so that pressing the brake pedal is more manageable. If there is a vacuum leak, the booster will not work correctly, and the brake pedal will be harder to press.
Also, if there is a vacuum leak, it can cause other problems, such as:
- Reduced engine power
- Rough idling
- Stalling
- Check engine light
If you hear a hissing sound under the dash and your brakes are hard to press, it is essential to have your car inspected by a mechanic as soon as possible. The mechanic will be able to diagnose the problem and make the necessary repairs.
