Brake pedal is stiff and makes a noise like leaking air when pushed. What is the problem?

With the engine off, put your foot on the brake pedal and press down. The pedal should go nowhere. With foot still pressing on pedal, start the car. The pedal should move down. If not, could be an issue with the servo such as a cracked / leaking air hose or an issue with the master cylinder seals.

If your car has power brakes, a slight hissing noise when depressing the brake pedal is not unusual. However, if you are having issues with the brake pedal felling stiff or hard, then you may have a vacuum leak in the power brake booster. If that is the case, it must be replaced.

a brake pad is a small solid piece of steel with some brake material glued or riveted to it. i can't even think how a brake pad could make any noise. If you mean the brake pedal makes an air leak noise when you push it down, then i think you need a new vacuum booster.

No, your brakes should have a stiff pedal regardless of anything going wrong electrically in the car. You better look for brake fluid leaking out. Try not to let the reservoir run dry while you're looking for the leak, as that will introduce more air into the lines. Let us know what you find and if we can help any further.

HI this sounds like the vacuum booster has a leak in the diaphragm. That is why you hear that sound when you push on the brake pedal. With out the vacuum to help this leaves you with a very stiff brake pedal. You will need to replace the Booster which is located behind the brake master cylinder and on the firewall. Good luck

Check for fluid leaks and your brakes. If you see no leaks and your brakes are in good shape replace the brake master cylinder and bleed the system. The air you hear is because the pedal went to the floor. If the booster goes bad the pedal will get so hard you can hardly push it at all. I think you will find if this happened suddenly either you have a major leak or the master cylinder went bad.

air may have gotten into your brake lines. try bleeding your brakes. this will require two people

this noise is caused by a defective power brake vacuum booster, (big round thing behind the master cylinder) the diaphragm is leaking vacuum.

your power brake booster needs replaced ,it work off engine vacuum and when the seal inside leak there is no power assist for the brakes

this noise is a vacuum leak at the power brake vacuum booster due to a tear in the booster vacuum diaphragm, u should have this replaced ASAP, it the leak gets worse the brakes will become very hard to push and will limit your ability to make a safe and timely stop.