Air is crucial for your car’s internal combustion engine to run smoothly. But it can become a major cause of inefficiency and safety issues if it finds its way to the anti-lock brake system (ABS). There are a number of ways that air can get into your car’s ABS, but most of the time, it happens during repairs, such as when you’re changing wheel pistons and master cylinders.
What makes the air problematic is that, unlike the brake fluid, it is compressible. When you press the brake pedal, the air compresses first before the oil can act. This gives a “spongy feel” to the brake pedal. If you get to this point, you need to bleed (remove) the air from ABS. So, how do you do it?
In this post, we are going to provide a step-by-step guide on how to bleed ABS module on your own without using a scan tool.
How to Know Your ABS Module Needs Bleeding
Before we cover the process, it is important to understand the ABS system first. It’s also important to be sure that the system really requires bleeding?
ABS, an abbreviation for anti-lock braking system, provides the driver with the option of using the car’s steering wheel while braking. This gives the driver optimal control, especially when driving in hard situations.
The system works with speed sensors that detect when your vehicle’s wheels are locking. This triggers the application and release of wheel brakes in pulses. The effect is that wheels spin smoothly without spilling.
If you hit the brake pedal and it gives a spongy feeling on foot, it is an indication that the ABS might be having some air. Another sign is when the car’s brakes take longer than usual to respond. If the brake system has been repaired recently, it will also be a good idea to consider bleeding it.
When you notice the signs we have listed above, it is time to bleed the system.
How to Bleed ABS Module Without a Scan Tool
The process of bleeding your car’s ABS module is not complicated but can take some time because each wheel is handled separately. So, here are the seven key steps that you should follow to bleed your car safely and correctly.
What You Need to Bleed Your ABS Car Module
- Car jack
- Drip bottle
- Brake fluid
- Car stands
- Lug wrench
Step 1: Park the Car on a Level Surface
Select a flat surface that also has good ventilation and lighting to park your car. Since you will need to access each wheel separately, make sure the car is also positioned some distance from the wall. Then, ensure the vehicle’s emergency gear is engaged. That way, it won’t start moving when you are bleeding the ABS module.
Step 2: Remove the Car’s Wheels to Expose the Bleeder
Put on your gloves, and then lift the car to a level that you consider comfortable. Loosen the nuts securing the wheels and remove the wheels of your car. This will give you access to the wheel bleeders. Remove the cup used to keep dust away. This will also be an excellent point to inspect the wheel and steering system.
Step 3: Connect the Brake Bleeder to the Drip Container
Using a lug wrench, loosen the brake bleeder screw and connect one end to the tubing and the other to the drain container. You may want to ask a friend to hold the drain bottle as the brake oil runs out.
If you’re on your own, attach the drain container to strands and rest it somewhere firmly so that it will not come off as the brake oil runs into it.
Step 4: Locate the Master Cylinder (Fluid Reserve) and Fill It With Brake Fluid
Under the hood of your vehicle, locate the brake fluid reserve. This should be a transparent container that features metal tubes (lines) that run through to all the wheels of the vehicle. Then, top up the reservoir and ensure that it will not fall too low. If you let it empty, there is a risk of air getting sucked into the brake lines.
Note: You MUST only use the right fluid for the car’s braking system.
Step 5: Pump the Brakes Continuously and Catch the Brake Oil on the Drain Bottle
Once the drain container is fitted correctly, pump the brake continuously to push the oil on each wheel until it starts running out smoothly without bubbles.
If the oil on the reservoir starts running low, refill it so that it does not suck down air. Now, repeat the process on all four wheels until you are sure there are no bubbles on the brake system.
Step 6: Tighten the Bleeder Screw and Refill the Reservoir
Once you are through bleeding one wheel, it is time to get everything back. You need to start with returning the bleeder screw and then fixing the dust cap.
Make sure to keep pressing the brake pedal until the bleeder is tight to avoid more air getting sucked back. If this happens, you have to repeat the entire process.
After tightening all the screws, refill the brake fluid reserve to the recommended level. Repeat the process for all four wheels.
Step 7: Check for Leaks and Re-attach the Wheels
When you get to this point, there is one more thing that you need to do: check for leaks. So, ask your friend to press the brake pedal and carefully check all the bleeders and the entire brake system to ensure there are no leaks. If you notice a leak, get it fixed right away before getting the car on the road again.
If everything is okay, meaning that the bleeders are firmly done and there are no leaks, it is time to refit the wheels of your car. Finally, test drive the car to confirm that the brakes are working well as expected.
Remember also to clean up the working area. If you have hazardous waste, such as used up brake oil, dispose of it correctly. Leaving it to get washed up downstream can damage the aquatic ecosystem. So, take it to a waste management firm that can dispose of it correctly without harming the environment.
What sequence should you follow when bleeding ABS module?
The recommended sequence is right-rear, left-rear, right-front, and left-front. To determine the sequence, you should first go for the wheels that are located furthest from the master cylinder. Then, finish with the ones that are closest.
Can you bleed ABS module without a scanner?
Yes, you can. You need to open the bleeders located on the wheels, strike the pedal to pressurize the brake oil plus the trapped air to get out. Then, close the bleeder and repeat the process for all the wheels.
For some people, how to bleed ABS module is seemingly a tough process, especially without the scan tool. However, it’s not as complicated as it sounds. All that you need to do is follow the steps we have listed in this post. However, it is important to prepare adequately and stay focused because the job is repetitive. Remember that although the job can be done on your own, it will be better to have a friend help out.
Again, thanks to Blake’s Garage for the awesome video tutorial.