Will Air in Brake Lines Cause Brakes to Lock Up? Diagnosing and Fixing

In order for a braking system to work flawlessly, it needs to be well-maintained and free of any faults. When you own a car for a long time, you soon realize the importance of being proactive and inspecting your brakes regularly. But will air in the brake lines cause brakes to lock up? Could they inevitably lock up?

Brake fluid problems highlights

• Level of urgency:super-urgent
• DIY diagnostics:usually,impossible
• DIY repairs:impossible
• Price for repair:$250 - $650
• Common symptoms:pedal goes to the floor, braking efficiency low, leaks
• Commonreasons:brake lines leaking, low fluid,badfluid
• If ignored:no brakes, getting into accidents, poor safety when driving

Common Symptoms of Air in Brake Lines to Watch Out For

• Soft Brake Pedal - One of the main symptoms you ought to look for is a soft, mushy, or spongy brake pedal. Air creates bubbles that tend to compress more easily than liquid and thus lead to a softer brake pedal engagement.
• Brake Fade/Reduced Braking Power - If your brakes need a harder push to stop the vehicle, there is a great deal of chance that your brake lines have air inside of them. Moreover, if your braking distances are lengthened, it can also be caused by air present within your brake lines.
• Increased Brake Travel - Another symptom to look out for is when your brake pedal only engages the brakes when you push it all the way in. If your brake pedal travel is longer than usual, you should consider diagnosing your brake lines.
• Vibrations and Noises While Braking - When air accumulates inside of your brake lines, it disrupts the hydraulic pressure and causes your brakes to be inconsistent. This also leads to vibrations, pulsating, or unusual noises. Also, be aware that these can be caused by warped rotors.
• Air Bubbles in Brake Reservoir - Last but certainly not least, if you happen to find air bubbles forming in your brake fluid reservoir, it is an obvious sign that your brake lines have air in them.

Causes of Air in Brake Lines

• Improper Maintenance - One of the most common causes of air in brake lines is improper maintenance, specifically, incorrect brake bleeding. This can occur when refilling brake fluid after it has been depleted, not ensuring proper fluid levels, or allowing air to be sucked back into the system during the bleeding process
• Contaminated Brake Fluids - Another relatively common cause is contaminated brake fluid as foreign objects such as dirt and water can cause bubbles quite easily and thus affect the system's ability to transmit adequate hydraulic pressure.
• Line Damage/Leak - If one of your brake lines is leaking or is damaged in other ways, that can very easily create a pathway for air to get in.
• Brake Overheating - If you overwork your brakes, you can cause brake fluid to start boiling. As we all know, when a liquid boils, it tends to create bubbles.
• Neglect- It is known that brake fluid absorbs moisture over time which can decrease the boiling point and create bubbles.

Diagnosing Air in Brake Lines

Now it's time to tell you how you can approach diagnosing if there is any air within your brake lines. To do so correctly, you should park your car on level ground, engage the parking brake, and take the key out of the ignition.

Sometimes all it takes is for you to take a look at your master cylinder, your lines, all of your calipers, and wheel cylinders, to see if there could be a leak from which air could enter the system.

You should also take note that brake fluid tends to have a yellowish/brownish/amber hue and can easily stick to your fingers due to its oily properties. It does not evaporate, it corrodes nearby steel, and it typically leaves a pathway to where it leaked from.

If a simple visual inspection won't do, you will have to gain access to your brake fluid reservoir and check your brake fluids in your master cylinder reservoir.  A low level of brake fluid typically means that air has gotten in and that your brake fluid left the reservoir. This is likely the easiest and most certain method of checking whether you have air in your brake lines.

Fixing Air in Brake Lines

The most effective way to get rid of air from within your brake lines is to perform something called brake line bleeding which includes pushing the trapped air away from your lines and making sure only your brake fluid is left.

Essentially, what you need to do is to remove everything from your lines that can be compressed because brake fluid is designed to not compress under load and that is what makes it gives it its hydraulic properties.

Bleeding the Brakes: Step By Step Guide

Step 1: Gather Your Tools and Prepare Your Vehicle

First of all, you need to make sure you got the right tools for je job. This includes the right brake fluid type (check your manual), a piece of clear tubing or a brake bleeding kit, a wrench or a socket set, and jack stands.

Be sure to park your car on level ground, engage the parking brake, lift the car using a jack, and secure it with a pair of jack stands.

Step 2: Bleeding the Brakes

Prop up your hood, locate the brake fluid reservoir (check the manual), open it up, and leave it open. Start with the wheel farthest from the reservoir itself and attach a clear tube to the bleeding valve.

You should put the other end of the tube into a container filled with some brake fluid to prevent air from being sucked back into the reservoir. It's also a good idea to have someone pump the brake pedal while doing this.

When the pedal is pressed firmly, open the bleeder valve for the air to escape, and close the valve when the brake pedal is released. Repeat this process a few times until you see a consistent stream of brake fluid without any air bubbles in it.

While doing so, check the reservoir every now and then, and be sure to top it up if it gets too low. Proceed to other corners of the car but be sure to do the ones farther from the reservoir first.

Step 3: Check the Brake Fluid Level

Once you are positive that there are no bubbles inside the system, check the brake fluid level and make sure it's at a proper level. Properly close all the bleeder valves, remove the jacks, and then test out your brake pedal to see if it's firm and consistent all the way through.

Make sure to properly tighten your valves as not doing so can introduce a lot more air into your brake lines.

Brake Line Maintenance

Once you finish bleeding your brakes, it's important to check a few things to ensure air doesn't find its way into your brake lines again.

Firstly, you should check for leaks and make sure to refill the brake fluid reservoir after driving for a little bit to be sure the brake fluid is at its recommended level. Inspect the rest of the brakes and be sure to follow a pre-scheduled maintenance plan recommended by your manufacturer.

The idea here is to take care of your braking system at all times, not just when something is wrong with it. To make the most out of all of this, you should also focus on OEM replacement parts and brake fluid compounds specifically designed for your type of car.

Conclusion

At the end of our "Will Air in Brake Lines Cause Brakes to Lock Up" article, we can safely say the presence of air within your brake lines shouldn't be a reason for your brakes to lock up.

If your braking system suffers from other issues such as ABS issues, faulty brake parts, contaminated fluid, a stuck brake caliper, or brake master cylinder issues in addition to having air inside your system, then this could cause the brakes to lock up, but not because of the air itself.

Either way, your brakes are always going to be your number 1 safety feature which is why you need to make sure to maintain your brakes according to what the manufacturer says. If you do that, then having air inside your brake lines is likely going to be the least of your worries.