Auto manufacturers equip vehicles with safety features to keep drivers and other road users safe. One of these safety features is the anti-lock braking system (ABS). The anti-lock braking system regulates your car in heavy braking situations.
Any time you do any brake system maintenance or repair, such as replacing calipers, master cylinders, wheel pistons, or hoses in your brake system, air can get trapped in the brake circuit. The problem is, the trapped air is compressible.
So, whenever you press the brake pedal, the air inside the brake circuit must be compressed before the hydraulic fluid. This will cause a spongy soft feeling when depressing the brake pedal. Plus, the stopping distance will increase.
You have to bleed the ABS module with a scan tool to remove the trapped air. I understand that not everybody can afford a scan tool. So, in this article, I’ll show you how to bleed ABS without a scan tool and how to know when the ABS needs bleeding.
How do I know if my ABS module needs to bleed?
First of all, we have to know the meaning and purpose of an ABS. ABS is the abbreviation of (Anti-locking Braking System). This electronic device system processes the signal from the ABS sensors. The car computer collects this data and creates electronic information that ensures the system works as predefined by the car manufacturer.
In other words, the ABS module is a microprocessor that analyzes data or runs a diagnostic test on the hydraulic braking system and the wheel speed sensors to know when to release braking pressure to any wheel that is about to skid or lock up.
The most common symptom of air in ABS module is if the brake pedal feels spongy when you depress it. The reason is that the trapped air in the system must be compressed before the pressure applies to the brakes. Bleeding the brake system is all you need to address the underlying issues.
- Other symptoms that indicate the ABS needs bleeding include;
- The illumination of the ABS warning light on the dash
- The appearance of the ESP warning light on the dashboard
- The ABS may activate even when it is not needed. The brake pedal may suddenly vibrate and jerk
- A lousy ABS module or one that needs bleeding will throw error code U0121.
Read Also: Brake Pedal Goes to Floor When Engine Running [Causes and How to Fix]
Can you bleed an ABS system without a scan tool?
You can bleed your ABS without a scan tool if your vehicle has ABS module bleeder screws. In the next section, I’ll provide you with adequate information on how to bleed the ABS module without a scan tool. However, if you need a more straightforward process to bleed your ABS module, you need a scan tool. You can search for ABS scan tool rentals to rent the tool from your neighborhood.
How to bleed ABS module without scan tool: Step By step.
Bleeding the ABS module is not that hard to perform. But it might take some time because you need to bleed each wheel separately. So, here are simplified steps on How to bleed the ABS module without a scan tool.
Step 1: Park the vehicle
Firstly, park the car on a flat level in a place with good lighting and good ventilation.
Step 2: Lift the vehicle
Block off the wheels with wheel chocks. Lift the vehicle and support the wheels with jack stands. Remove the four wheels to reach the bleeders easily.
Step 3: Drain the brake fluid
With the wheels suspended, locate the brake fluid reservoir in the engine bay. Empty the old hydraulics in it and replace it with recommended brake fluid type. The brake fluid reservoir is typically a transparent plastic container attached to the master cylinder.
Step 4: Bleed the wheels
Locate the bleeding port in the brake caliper and wheel drums and remove the dust cap. Now, slack the bleeder valves and let the brake fluid rush into a container. You can connect a small tube to the bleeder valve and put the other end into the container for easy draining.
Refill the brake fluid and tell a friend or your assistant to pump the brake pedal continuously. The pumping will push out the trapped air in the system along with the brake fluid. Tell the assistant to hold down the pedal while you lock the bleeder valve. Ask him to pump the pedal five to six times and hold it down. Once he’s holding down the pedal, open the bleeder valve and lock it once the fluid stops rushing out.
Remember to keep checking the fluid reservoir every time fluid rushes out of the bleeder valve. Air will get trapped in the system if the fluid in the reservoir runs below the minimum level. Repeat the process on each wheel, starting from the rear wheel on the passenger’s side to the rear wheel on the driver’s side. When you’re done with the rear wheels, move on to the front wheel, starting from the passenger’s side.
Step 5: Check for fluid leaks
Once you are done with the above steps, ask your assistant to depress the pedal continuously so that you can see if there’s a leak on any of the wheels. After that, refill the reservoir with fresh fluid.
Step 6: Test drive the car
Attach the wheels and lower the vehicle. Re-tighten the wheels on the ground and test-run the vehicle to see if the ABS module works as it should.
This is a simplified way of bleeding the ABS module without a scan tool. It’s easy but a little time-consuming.
Read Also: No Brake Fluid Coming Out When Bleeding [Causes and Fixes]
Frequently Asked Questions (FAQs)
Q: How do you bleed the ABS module with the scan tool?
If your ABS module is not equipped with a bleeder, you have to use a scan tool to perform proper bleeding instead of you to manually activate ABS pump. Using Autel Scanner MaxiCheck Pro will make the job very easy and save much time. But if you can’t afford the tool, you can try one of the cheapest ABS bleed scan tools on Amazon.
You should connect this tool to the OBD11 port under the steering wheel in most cars. It will communicate with the ABS module and activates the pump; then, you follow the procedure to cycle the ABS solenoids to bleed out air.
Q: Can I drive with a bad ABS module?
Yes, you can drive with a bad ABS module. However, the illumination of the ABS warning light on the dashboard means you should take caution while driving the vehicle. While you don’t necessarily have to stop the vehicle, some ABS functions will stop working. For instance, the ABS module will not send braking pressure to any wheel about to skid or lock up.
Q: How much does it cost to fix the ABS module?
The cost of fixing a lousy ABS module depends on factors like your vehicle make and model, location, and the technician fixing the vehicle. However, the average cost for ABS module replacement ranges from 340$ to 1,100$. It is important to note that the price can be higher or lower than this.
Q: How long should an ABS module last?
The longevity of an ABS module depends on your maintenance culture and driving habits. ABS modules on newer model cars can last as long as ten years or 100,000 miles if you imbibe a good maintenance culture. But it’ll fail much earlier if you don’t maintain it properly. Maintaining the proper fluid level and doing a scheduled brake fluid flush will extend the lifespan of the ABS module.
Q: Is it safe to remove the ABS fuse?
Yes and No. If you remove the ABS fuse, the brakes will still work, but you’ll miss some braking features, such as the ABS module preventing the wheels from skidding or locking up. However, if you need full control of the wheel when racing or want to skid the wheels, removing the ABS fuse is safe.
Q: Can a bad ABS module cause transmission problems?
Yes, the ABS can affect transmission performance. In some vehicles, the transmission control module collects data from the wheel sensors or ABS for optimal performance. If the ABS module becomes faulty, it will send a false or no reading to the transmission control module, invariably causing transmission problems like delayed shifting, hard gear shifting, limp mode, and poor to jerky gear shifts.
When you finish bleeding the ABS module and the whole brake circuit, you must ensure everything is in place, and there is no leak. Ask the helper to continuously press the brake pedal to detect if there’s anything wrong.
This is the most simplified guide on how to bleed abs module without a scan tool you’ll find anyway. It’s easy and safe. If you don’t trust your gut or don’t know the working principle of your brake system, contact a professional mechanic to bleed the ABS module.