Air in your brake lines is a serious issue that can cause your vehicle’s brakes to be unresponsive. This will create unsafe driving conditions for you and others on the road. Air in a vehicle’s brake line is one of the most common causes of brake failures.

The most common symptoms of air in a brake line are a spongy feeling when pressing down on the brakes, brakes feelings softer than normal, and brakes that depress farther than they should. All three of these symptoms commonly indicate issues with air in your brake line.

This guide will provide you with all of the information that you need to accurately identify air in your brake lines so that you can address them appropriately. It is important that you address air in your brake lines as soon as possible.

Driving with air in your brake lines will cause unsafe driving conditions for you and others. Because of this, you should avoid driving any vehicle that you have determined has air in its brake lines.

Symptoms Of Air In Brake Line

The common symptoms of air in a brake line are braking feeling spongy, brakes feeling softer than normal, and brakes that depress farther than they should. If you are experiencing any of these issues with your vehicle, it is likely that you have air in your brake line.

These issues will be discussed in more detail in the list below. You should use this information to identify your issue accurately so that you can address it appropriately. It is not advised that you operate a vehicle that has air in its brake line until the issue is resolved.

1. Brakes Feel Like A Sponge

If your brake pedal feels spongy when you press down on it, it is likely that you have air in your brake line. You will likely notice immediately when your brakes do not have the same firmness as they once did.

This will be especially apparent in the spongy sensation that you will get when there is too much air in your brake line. If your brake feels spongy and soft, then you likely have a large accumulation of air in your brake line.

You should consider not driving the vehicle until you are able to resolve this issue. When the brake lines have enough air in them to soften the brakes enough to feel like a sponge, there is a high likelihood of brake failure.

If your brakes feel softer than normal when pressed down on, you likely have some degree of air accumulation in your brake line. As previously mentioned, it will not be hard to notice that your brakes feel different.

You will also notice that your brakes are much less responsive and effective when driving. Because of this, your vehicle will not be safe to drive until you remedy these issues.

2. Brake Pedal Depresses Too Far

If you are able to easily press your brake pedal all the way to the floor or notice that it depresses much easier than you would like, then you likely have air in your brake line. The brake pedal is not meant to depress all the way to the floor easily.

If you find that when you go to press the brake pedal that it depresses almost instantly with little to no pressure, this is a strong indication that you have air in your brake line. You will also notice that your brakes are less efficient and responsive while driving.

It is not safe to operate a vehicle with a brake pedal that depresses too far. You will need to address the air in your brake line before the vehicle will be safe to operate.

How Does Air Get Into Brake Lines?

Air gets into your brake lines over time due to the way that your brake pads wear down. As your brake pads wear down, they will need to travel further to properly stop your vehicle. Your brake caliper will expand to compensate for this to maintain a uniform distance at all times.

To do this, your vehicle’s hydraulic pistons will be forced to extend which will cause empty space in your hydraulic system. This empty space will become filled with air as your worn brake pads require more brake fluid to maintain optimal function.

Unless you are closely monitoring your brake fluid, your system will draw in more air as your vehicle has to work harder to depress your worn brake pads. This air will cause your brake pedal to feel soft or spongy and lead to dangerous driving conditions.  

How To Fix Air In Break Lines Issue?

To fix air in your brake lines, you will need to bleed the brakes of the air. This will typically restore the full functionality of your brake system. You can choose to have your brake bleeding done by a mechanic or do it yourself if you have the proper experience and tools.

Both of these methods for brake bleeding will be compared in the section below. This can help determine with is best for your particular situation.

Brake Bleeding At A Mechanic

You can get your brake bleeding done by a mechanic for an average price of $125. This includes all labor costs that are generally incurred during brake bleeding. Brake bleeding is fairly simple as far as vehicle repairs go, making it one of the cheaper issues to resolve at a mechanic.

You can expect your brake bleeding to be completed within 24 hours once the process has been started. Keep in mind that the overall price of your brake bleed will depend on your vehicle, location, and choice of mechanic.

Brake Bleeding DIY

Brake bleeding can be done at home if you have the proper tools and experience. You will need another person to assist you during the brake bleeding process, along with safety glasses, wrenches, a container to catch the drained brake fluid, and a vinyl tube. The process to do this will be listed below.

Fill Up With Brake Fluid

To start the process of brake bleeding yourself, you will need to ensure that the brake fluid in your vehicle’s engine compartment is only filled to a quarter-inch below the maximum level. You will then need to locate the bleeder screws

Locate Bleeder Screws

You will need to remove the tires to access the bleeder screws. The location of these bleeder screws will vary based on your vehicle’s make and model.

Once you have jacked the car up and removed the tires, locate the bleeder screws on your vehicle and loosen them. If you are having issues finding your bleeder screws, consult your vehicle’s manual for more information.

Hook Vinyl Tube To Bleeder Screw

Once you have loosened your bleeder screws, hook the vinyl tube to the bleeder screw and place the other end of the tube in the container meant to catch the brake fluid. You should start with the bleeder screw located near the back right tire.

Press Down On Brakes

Have someone press down on the brakes all the way while you hold the vinyl tubing in place. You should have the brakes depressed throughout the entire next step of this process. You should be careful to ensure that no brake fluid is spilled out of the container or onto your person.

Bleed Off The Fluid And Air

While the brakes are depressed, loosen the bleeder screw and allow all of the brake fluid and air to be released. This will cause all of the brake fluid to be drained into the container through the vinyl tube. You should ensure that the brakes are depressed all the way for this process to be successful.

Tighten Bleeder Screw

While the brakes are still depressed, tighten the bleeder screws. You should not release the brakes during this time as it could cause air to be sucked in. You should repeat this step until all the air and fluid have been drained from your brake lines.

Refill The Master Cylinder

Once you have tightened all of the bleeder screws, you should replenish the master cylinder with fluid to the proper levels. Once you have done this, you will have successfully removed all of the air from your brake lines.

Keep in mind that over time, more air will accumulate. This means that you could have to bleed your brakes again sometime in the future. If this process is not something you feel comfortable with, you should consider taking your vehicle to a mechanic.

Final Thoughts

This guide has provided you with all of the information that you need to identify air in your brake lines and help you resolve the issue. Because the air in your brake lines could cause your brakes to fail, you should not operate any vehicle that you have determined is experiencing these issues.

This guide can help you resolve the air in your brake lines so that you can get your car operating safely as soon as possible.