How To Bleed Air From ABS Module? - Vehicle Freak

• Emma Davies

Updated on July 27, 2022

If your ABS brake system is just not feeling as responsive as it once did, it may mean that there is air in there. so your next question is how to bleed air from the ABS module and why.

This process involves removing all the air in the system and has to be done as air is compressible and if there is air in the brake system then your brakes will feel soft and will definitely not work as well.

The easiest way to bleed air from an ABS module is by using an . Simply navigate through the menus and follow the instructions.

It’s still possible to bleed an ABS system without a scanner, but it’s going to be a more complex process. We’ll discuss both methods in detail, so you can decide which one is more suitable for your situation.

How Do I Know If My ABS Module Needs Bleeding?

The ABS is your Anti Locking Braking System that processes information from individual wheel speed sensors on each wheel. It also uses the hydraulic brake system to control when to release the brake pressure on a wheel that is about to lock up.

Essentially it is designed to prevent your wheels from locking up if and when heavy brake pressure is applied. this helps your vehicle avoid hydroplaning or skidding.

ABS has been available since the 1980s and is a safety feature that allows you to slow down quickly and in a more controlled manner. But how would you know if your ABS module needs bleeding?

You may notice that your brake pedal feels weirdly low and sluggish to respond when you are pressing it in normal driving conditions. You may also notice that your brakes feel spongy. These are all signs that your ABS module needs bleeding.

How to Bleed Air from ABS Module

Any time your brake lines are open then air will be introduced so if you are changing components such as wheel cylinders, ABS units, or calipers then this has the potential to cause an imbalance in the system and create spongey brakes.

It’s recommended you change the brake fluid every time you bleed your brakes or do any work to them to prevent any debris from being pushed through the system and causing damage. Let’s take a look at how to bleed air from the ABS module.

With a Scan Tool

Using your scan tool activates the valves and allows air to be forced through the system which is essential for new vehicles.

Before you begin, make sure you clean the reservoir on the brake mass cylinder as any dirt present will cause damage and can shorten the service life of your hydraulic system.

1. Start your car and connect the diagnostic tool. Every system is different so you may need to look at the information booklet that came with your tool to help you find the correct menus.
2. Once you have located the right menu your software should have an option for which area of your brakes you want to bleed.
3. Select the brakes you want to bleed and follow the instructions then your system will run the respective release valve cycle.

Here is a great video to show you exactly how an affordable scanner can help you to bleed air from the ABS module.

Without a Scan Tool

Bleeding the ABS module is not a difficult job, but it does take some time to do if you don’t have a scan tool. You need to bleed each wheel individually and it does require some tools.

Steps to Bleed the ABS Module:

1. Start by making sure your vehicle is parked in a well-lit and ventilated area with the parking gear engaged and emergency brakes deployed.
2. Use your car jack to lift your vehicle to a comfortable level so you can remove each wheel and gain access to the bleeders.
3. Go under the hood to remove all the brake fluid in the reservoir and replace it with fresh.
4. Find your brake bleeder screw and use the right bleeder wrench to remove the dust cap and take a vacuum hose and tubing with one end in the bottle and the other end at the bleeder screw.
5. Pump the brakes until all the fluid has been emptied and check thoroughly that it is entirely empty.
6. Before you reattach your bleeder screw get someone to press the brakes down all the way and hold it to release any trapped air. Keep the pedal depressed until the bleeder screw has been replaced as tight as it was before.

How Do I Know If My ABS Module Is Defective?

If your ABS isn’t working properly then this can cause some serious safety issues for you when you’re driving.

A flashing or lit ABS light is the most predominant sign that there is a fault, but on older vehicles, this may appear as the check engine light instead. You can lose traction or even powerslide when you attempt hard braking.

Another fault that you cannot ignore is if your brake pedal doesn’t respond which shows the ABS module has completely failed after the gradual loss of function.

Before they completely stop responding you will find that your brake pedals require more force to generate the same amount of power. You might also notice that your brakes begin squeaking as a result of them locking up when you drive which creates a squeaking or clicking noise.

When the ABS system is functioning properly it stops the wheels from locking up during hard braking and prevents traction loss.

If you don’t bleed your brakes when required then this can cause longer stopping distances and weak brakes as the air stays in the system and reduced the hydraulic pressure your caliper pistons need to grip the brake pads against the rotor.

FAQs

Do you bleed ABS brakes with the engine running?

Bleeding your ABS system and performing brake fluid replacement will require the engine to be running during specific stages in the procedure. This can be done by starting the car manually or using a computer to command the motor to run.

Will air in brake lines go away?

No air can escape the system if it is tightly closed, even air bubbles will dissolve as soon as pressure is released and brake fluid heats up.

How do you know if there’s air in your brake lines?

If your brakes feel spongy, defective, or loose when you press them down then this can be a sign that there is air in your brake lines that need to be bled.

Will a brake system bleed itself?

A brake system will not be able to bleed itself and you should either manually bleed them or use a scan tool to successfully bleed them and remove the air from the system.

Conclusion

Maintaining the full function of your brakes is an immensely important part of any vehicle as increased stopping distances and weak braking can result in dangerous driving conditions and even cause serious accidents in the worst-case scenarios.

Making sure you bleed your brakes correctly is significant to remove any air from your brake lines as this needs to be done either manually or with a scan tool to keep the best possible function from your car.

Now you know how to bleed air from the ABS module, remember If you think your vehicle isn’t safe to drive or you’re not confident in your brakes’ ability to perform then you should never drive your vehicle as it can put you and others in danger.

Here are some other articles to read:

What Does TCS (Traction Control Light) Mean on a Car?

What Is The Emergency Stab Braking Method?

How To Tell Which Abs Sensor Is Bad?