Air In Brake Line Symptoms

Brakes are largely the most important safety feature of your vehicle. When the brakes do not work, then you may be at a greater risk of getting into an accident. One of the reasons brakes fail in having air in brake lines. So, what are the symptoms of air in the brake line? How do you rectify this situation?

Air in the brake line will mean the brakes do not work as expected. You may experience a spongy brake pedal. The feeling can be described as having to press the brake for longer than usual to feel the car slowing down. Generally, you end up with ineffective brakes.

The brake lines are vital for circulating the brake fluid in the braking system and keeping the air out. Introducing air into the brake fluid reduces its effectiveness. That is the last thing you would want since the car would not stop as effectively as it should.

We understand you might be curious as to what would make the brake lines have air, how to tell there is air in the brake line, and how you can get the trapped air out of the brake line. We discuss all of that in this guide.

How To Tell If There’s Air In Brake Lines

When you can tell there is a problem with the brake lines, you can know when to take the vehicle for repair. Below, we look at the symptoms of air in the brake lines.

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The brakes feels soft

Normally, you would feel some resistance when you step on the brakes. That resistance is good, showing you that the brakes are working as they should.

That feeling of resistance is gone when you have air in the brake line. You end up with a soft or mushy feeling. This is enough message that there is something wrong with your brakes.

The brakes feel spongy

You might wonder what the difference is between having a soft and mushy brake pedal and a spongy pedal. When spongy, the brake tends to bounce back a bit when you release the pedal.

Also, you may notice that you need to hold down the brake pedal for the brakes to work.

Braking performance is compromised

Another thing you may note is that it now takes a lot more distance to stop when you could do so a lot faster before.

There are over 35,000 crashes each year, with some related to braking issues; you would not want your vehicle’s braking performance compromised. So, when you notice a decreased braking performance, that is your cue that you have to get the brakes checked and repaired.

How Does Air Get Into Brake Lines

We have already established that air in brake lines is not good. However, what even causes air to get into brake lines in the first place?

Brake fluid is not bled

You may have recently made a few changes to the brake system, such as changing the brake pads. During this time, the mechanic opened the brake line for some reason and did not bleed it correctly.

Air In Brake Line Symptoms

When you have brake fluid that is not bled, you have a spongy feeling of the brake pedal, or the car does not stop as fast as you would expect.

Old brake fluid

You cannot continue using the same brake fluid for years. It can also start to break down with time and still absorb water. When it absorbs water, you will end up with air bubbles in the brake fluid.

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We recommend that you should be keen on changing the brake fluid based on the manufacturer’s recommendations. Most automakers recommend flushing and adding fresh brake fluid every two years. 

Pumping your brakes

This might be another reason you have air in the brake line. When you keep pumping, the fluid moves around and thus creating bubbles in the brake line.

This might not be the biggest reason you have air in your brake line, but it can be a contributing factor sometimes, especially for old brake fluid.

How Do You Get Trapped Air Out Of A Brake Line?

When you want to remove trapped air from the brake line, you can do it yourself if you have all the tools at home or have it done professionally at an auto shop or garage.

A mechanic will examine it to determine why air enters the brake line. It could be that the brake was not correctly bled the last time the bleeder valve was open, or you have a leak letting in air.

The mechanic will only know the right way to handle the situation after a proper check-up.

In case it is the first time you are experiencing brake bleeding, there is not much to worry about it in terms of price. Expect to pay an average of $100 depending on the location, vehicle model, or any additional repairs you may have to do.

Here is a video showing how brakes are bled to remove air from them

YouTube video

Can I Drive With Air In My Brake System? Is Air In Brake Lines Dangerous

One thing you should not do is keep ignoring air in your brake system. It is dangerous to keep driving with air in the brake lines. This is because the air in the brake line makes the braking performance less effective.

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You may have come across scenarios where someone crashed, and the reason was that their brakes malfunctioned. One thing about brakes is that they will not just fail overnight. They might show signs of failure for weeks before they finally let go.

When you understand the symptoms of air in the brake line, you will know when it is time to have the brakes checked and repaired.

Most of the time, removing the air from the brake line will not take long. If you have 15 to 20 minutes to spare, get to a garage and have the brakes bled professionally to ensure your vehicle stops as it should.

Here is how to flush your brake system

YouTube video

Air In Brake Lines Will Cause What Type Of Problem

So you might be experiencing the symptoms of air in brake lines and wonder if such a problem would lead to more problems in your vehicle. We discuss various scenarios below.

  • Can air in brake lines cause caliper to stick

Air in the brake is unlikely to make the caliper stick. Calipers largely stick because of a lack of lubrication, debris buildup, or corrosion. Unless there is no brake fluid reaching the caliper, then the calipers will not stick.

  • Can air in brake lines cause pulsating

Air in brake lines will also not lead to a pulsating feeling when you brake. That only happens when you have warped discs or rotors. The warping happens after excessive hard braking that ends up overheating the brakes. Also, worn brake pads will likely lead to worn-out brake pads.

  • Will air in brake lines cause brakes to lock up

When coupled with other things wrong with the braking system, it can end up with locked-up brakes. However, the air in the brakes alone would not lead to the brakes locking up. The main reason you may experience locked brakes is damaged ABS components. Others include broken calipers, brake pads, rotors, and using the wrong fluid for the brakes.

  • Will air in brake lines cause brakes to drag

Air in the brake lines does not cause the brakes to drag. It is largely because the brakes are tightly adjusted and rub against the rotor as you drive. Also, the bypass port in the master cylinder could be blocked by various contaminants, including dirt and debris. You may also notice the brake pedal return springs are worn, leading to dragging.

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Will air in brake lines go away?

Air in brake lines is not something you can wish, or hope will just go away. One thing for sure is that it will get worse. Having air in the brake line is generally dangerous, and you would not want to experience it. So, if you notice the symptoms, have the car checked and repaired.

What happens if brakes are not bled correctly?

Bleeding is important to remove any air bubbles trapped in the brake fluid. If the air is not removed, then the hydraulic pressure of the brake fluid is compromised. That is how you would not end up with a less effective braking system.

Why is my brake pedal still soft after bleeding?

You would still experience a soft pedal after bleeding because an inefficient bleeding job was done on the brake. That is not something you want as it makes the brakes riskier. Contaminated brake fluid is another reason you could be experiencing this problem. The brake fluid has trapped water, leading to more air bubbles. Leaking would also make the brake pedal feel soft even after bleeding.

Will bleeding brakes remove air from the master cylinder?

Yes. The bleeding process helps remove air from the whole brake system. You can be sure that once all the air is removed from the bleeder valve, even the one that was in the master cylinder is also removed. You will feel the brake pedal is different after bleeding is done correctly.

What causes brakes not to build pressure?

Pressure not building is largely because there is something wrong with the brake fluid. Most of the time, we found that it was a leak in the brake lines. This means you lose all the brake fluid over time; thus, there is nothing to build pressure. Also, a bad seal in the master cylinder leaves you with fluid leaks and air bubbles in the brake fluid.

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