It is very scary when driving and hearing a noise coming from your foot where it’s in contact with the brake pedal. This air sound is almost guaranteed to be related to some sort of problem with your vehicle’s braking system.
Air sound when pressing brake pedal usually indicates a problem with your vehicle’s brake booster, which is part of the system. Brake pedal helps make the application of the brake effortless.
Still, the good news is we’ll be going over the causes and effects and what you can do to fix air sound when pressing brake pedal.
Topic Summary
What Causes Air Sound When Pressing Brake Pedal?
Listening to an air like hissing sound coming from under your steering wheel when you step on the brake pedal can be worrying, especially if you’ve never experienced it.
Understanding the root cause of the hissing noise and the implications it could have for your safety and braking ability can be scary. Some causes behind the issue are:
Brake Booster Leak
The most common reason for making an air noise when you press the brake pedal is because of an air leak in the brake booster. The brake booster works by using vacuum pressure to assist your brakes.
When a leak occurs in the brake booster (due to a vacuum line or booster seal issue), you can hear a hissing sound.
Damaged or Worn Vacuum Hose
The hissing noise could also be a sign that the vacuum hose to the brake booster is damaged or worn. This hose can fall off, permitting air into the hose, which will also be a source of hissing upon brake pedal use.
Faulty Brake Booster Check Valve
The check valve in the brake booster prevents a vacuum from leaking out when the engine is stopped. Pressing on the pedal when there is no vacuum in the system can yield a hissing sound.
Internal Brake Booster Failure
The diaphragm inside the booster can become worn or damaged over time. Pressure on the brake pedal can cause a hissing noise.
Effects of A Faulty Brake Pedal
Ignoring a hissing or air sound from the brake pedal can lead to several issues:
Reduced Braking Efficiency: A defective brake booster means less help to apply the brakes, so you’ll need a longer distance to stop and a lesser overall braking performance.
Harder Brake Pedal: Without the force multiplication of the brake booster, a vehicle’s brake pedal can feel harder to press. It becomes harder to slow down and stop the vehicle.
Potential Safety Hazard: Compromised brakes are a serious safety concern, especially in emergencies where braking is definitely required.
How To Fix Air Sound When Pressing Brake Pedal?
Fixing is a must for air sound when pressing brake pedal. While fixing you should follow the following steps.
1. Inspect the Brake Booster
If possible, have a trained mechanic check the brake booster and the associated hardware for leaks, damage, or excessive wear and see whether the booster itself should be replaced.
2. Check and Replace Vacuum Hoses
Look at vacuum hoses that snake across the entire fascia. All can split, lose sealant, or even unthread. Replace any damaged hoses to ensure a secure, sealed connection.
3. Test the Brake Booster Check Valve
The mechanic can test the brake booster check valve for proper operation. The mechanic can be replaced if it is faulty and restore proper vacuum pressure.
Replace the Brake Booster
The brake booster is deemed unsafe and will need to be replaced if it is faulty or has seepage internally. This is crucial for the braking system, and regular maintenance is necessary.
Is It Safe To Drive with the Air Sound?
Driving the car with the brake pedal air sound is dangerous and should not be done. The noise is usually due to a leak in the vacuum lines coming from the brake booster or possibly a leak in the booster itself.
The brake booster assists in the braking process to help reduce the force that your feet will need to apply to the brake pedal. If there is a leak, it could cause the brake booster to become no longer assistive or partially non assistive and stop working correctly. Then, you will have to apply more force and effort to slow down your vehicle.
This can decrease your ability to stop your vehicle and increase your stopping distance, which is a recipe for disaster, especially in an emergency.
Also, it may be causing more damage within your braking system that can turn minor into a major problem if not taken care of, and drivable issues can become unsafe issues. This can happen and does without anyone realizing it.
If you do have a hissing noise from your brake system, strongly consider contacting a professional to take a look and fix the issue. Your safety must continue to be able to drive safely.
FAQs About Air Sound When Pressing the Brake Pedal
What Does It Mean If I Hear An Air Sound When Pressing Brake Pedal?
Another symptom of a bad brake booster is hearing an air or hissing sound when you push the brake pedal, which usually indicates there is a vacuum leak, most often in the brake booster, but sometimes in the vacuum hose or the check valve.
Is It Safe To Drive If My Brakes Are Making an Air Sound?
It could be a sudden hiss from under the brake pedal, a shoe of the brake that popped off but is still clamped by the backing plate, and that might prolong your brake pedals and make it firmer but will compromise your ability to stop your car as efficiently as you set off, which is not entirely safe for emergencies.
What Are the Causes of an Air Sound When Braking?
Some common causes include a leaking brake booster, a hole in a vacuum hose, or a leaking brake booster check valve. If the check valve, which stops the vacuum from coming back into the rest of the brake system after you let off the brake pedal, becomes stuck, vacuum pressure may fail to return to normal, and you could end up with a similar problem to my daughter. Similarly, if your brake booster itself has internal failure, you may experience the same symptoms.
How Can I Diagnose a Vacuum Leak in the Brake Booster System?
It is typically detected by visually inspecting the brake booster for worn vacuum hoses, by listening for any hissing sounds during braking (using a stethoscope), and by checking vacuum pressure and the brake booster’s check valve with the help of various diagnostic tools.
What Should I Do If I Hear an Air Sound From My Brakes?
If you hear an annoying hiss, be prepared for the mechanic to install a new brake booster, check valve, or vacuum hoses as soon as possible. A hissing sound can stem from various sources, including valve and hose failure, a sticking brake booster, a stuck spring, or a vacuum leak in the brake system.
Conclusion
When it comes to your vehicle’s brake booster system, you may hear an air or hissing noise every time you press the brake pedal. Pay attention to this indicator because it may mean that your brake booster system needs to be checked or repaired.
In order to stay safe and comfortable while driving, you should turn to a professional mechanic for diagnosis and repair to restore your car or truck’s brake system to its full capacity.