Here is a more detailed explanation:
The brake booster is a device that helps the driver apply the brakes. When you press on the brake pedal, the booster uses vacuum from the engine to amplify the force of your foot. This makes it easier to stop the car.
If the brake booster develops a leak, the vacuum will escape, and you may hear a hissing sound. The hissing sound will stop when you apply the brakes because the vacuum is no longer being used.
Here are some other possible causes of a hissing sound from a Jeep:
* A vacuum leak in the intake manifold.
* A vacuum leak in the hoses or pipes that connect the intake manifold to the brake booster.
* A malfunctioning vacuum pump.
If you hear a hissing sound from your Jeep, it's important to have the problem diagnosed and repaired as soon as possible. A vacuum leak can cause the engine to run poorly and can also make it more difficult to stop the car.
