Having your car’s braking system working properly is the most important piece of road safety equipment you could ever have.
One of this system’s most commonly ignored elements is the power brake booster check valve.
The valve may be tiny, but it makes all the difference in ensuring your brakes operate correctly.
This blog will address how the power brake booster check valve works and why it’s important to maintain it regularly.
Topic Summary
What Is a Power Brake Booster Check Valve?
Your power brake booster check valve is a very important part of your car’s brakes. It’s a tiny single side valve that blows in one direction only.
It’s usually on the brake booster, a small vacuum actuated disk that typically sits by the master cylinder on most newer cars.
The engine vacuum will travel to the brake booster using the check valve, which helps you to feel less pushed down on the brake pedal.
If you apply the brake pedal, the vacuum in the booster expands that force, making it easier for your car to slow down.
The brake without it would need far more power, and it would be much more difficult to get your car out of the way quickly.
How is the Brake Booster Connected?
The brake booster is connected to the brake system between the brake pedal and the master cylinder. It’s on the firewall in the engine bay.
An engine vacuum hose connects to the brake booster, which uses the engine’s vacuum force to brake.
The Breathalyzer pedal is connected to a push rod on the booster, which connects to the master cylinder.
Press the brake pedal, and the vacuum within the booster increases the pressure on the master cylinder so the brakes can engage more easily.
Moreover, the power brake booster check valve, typically on the booster, ensures that the vacuum only moves in one direction, retaining braking pressure.
How Does the Power Brake Booster Check Valve Work?
The power brake booster check valve regulates the air exchange between the engine and the brake booster.
It lets the vacuum created by the engine enter the booster but keeps air flowing out. This one way air valve ensures the booster maintains the vacuum pressure required to support braking.
With the engine on, the vacuum reaches the brake booster via the check valve. The vacuum remains in the booster, so there is a pressure difference.
Pedaling the brake pedal, this pressure differential enhances the force being applied and reduces friction during braking.
But the brake booster can’t supply enough vacuum pressure if your check valve fails or is jammed. That makes for sluggish or inert brakes that can be dangerous to drive.
Signs of a Faulty Power Brake Booster Check Valve
The wrong check valve can lead to many noticeable problems on your brakes. Here are some symptoms that typically aren’t good:
Hard Brake Pedal
A hard brake pedal is a common first indication of a failing check valve. You will find it hard to get the brake pedal in as the booster doesn’t assist you much.
Longer Stopping Distance
Without the help of the brake booster, your car will require longer to stop, increasing the chances of an accident, especially in a rush.
Hissing Noise
If the check valve fails, air could blow out, and you’ll hear hissing when you press down on the brake pedal.
Engine Performance Issues
Sometimes, vacuum leaks from a damaged check valve will affect the engine’s performance. It may give rough idle or low acceleration.
How To Check the Power Brake Booster Check Valve?
Your check valve is a simple to check for the ability to keep your brakes from going bad. How to see if it works as intended:
1. Locate the Check Valve
The valve typically attaches to the brake booster. It resembles a little plastic or metal valve with a hose attached to it.
2. Remove the Check Valve
Pull off the hose and unscrew the valve from the brake booster.
3. Test Airflow
Expend air through the valve both ways. There can be only one flow of air. If air leaks both ways or never returns, the check valve leaks and you must replace it.
4. Replacing a Faulty Check Valve
Replace the power brake booster check valve with a straightforward, low cost solution. If any of these symptoms occur or the check valve fails the airflow test, it’s time to get it replaced.
Most check valve replacements are fairly cheap and easy to install within an hour or less.
FAQs on Power Brake Booster Check Valve
What is a Power Brake Booster Check Valve?
A power brake booster check valve is a one way valve that forces the engine vacuum into the brake booster without forcing the air out. It is essential for improving the braking power, which helps the driver pull the vehicle to a halt with reduced effort.
How Do I Know If My Power Brake Booster Check Valve is Bad?
The main symptoms of a bad check valve are a hard pedal at the brakes, increased stopping distance, a hiss when you press the brake pedal, and possible engine malfunction such as rough idle or vacuum leaks.
Can I Drive with a Faulty Power Brake Booster Check Valve?
You shouldn’t drive with a bad check valve because it will ruin your brakes. Your braking power will suffer with more pedal effort and longer stops, which might prove dangerous in an emergency.
How Can I Test the Power Brake Booster Check Valve?
You can inspect the check valve by removing it from the brake booster and pulsing air back and forth. Air must only go one way. If the air passes both ways or is completely clogged, the valve is defective and must be repaired.
How Much Does It Cost To Replace a Power Brake Booster Check Valve?
Replacing a power brake booster check valve is typically not that expensive. The component is relatively cheap, and replacement takes just a few minutes. Many mechanics can do this repair at a very low labor cost.
Conclusion
This power brake booster check valve is small but a key component to keeping your vehicle’s braking system functioning smoothly.
Regular check-ups and repair of this valve could also avoid hard brakes, extra stoppages, and other dangerous issues.
If you notice the onset of a check valve malfunction, do not hesitate to have it repaired or replaced to maintain the health and effectiveness of your brakes.