What is A Brake Bleed?


Brakes are one of the most important features on your car, and sometimes they need a little bit of TLC themselves. Brake bleeds are a common procedure of giving your brakes back a little life, but what is a brake bleed?

What is a brake bleed? Brake bleeding is a simple way of releasing the air trapped inside of a hydraulic brake. This can be caused due to worn brake pads, poor driving, or even a leak in the break line itself. By bleeding your brakes, you are keeping your car much safer.

Brake bleeding is just part of regular maintenance. Let’s talk about why they are such an important part of keeping your car safe, and just how simple the process really is!

What Does It Mean to Bleed Your Brakes?

The idea of bleeding your brakes can seem scary. Most of us relate bleeding back to a medical idea, but that is not the case here. Brakes are a huge part of your car, and they help keep you as safe as they can. Sometimes brakes get air in them, which can cause them to stop working as well as they should.

Bleeding your brakes is essentially just removing the air that can get trapped in your brake system. This can be caused by worn-down brake pads, which can put air bubbles inside of your brake system. This causes the brake fluid and hydraulic pressure to drop leaving a soft or spongy feeling to your breaks. If you have a leak inside of your break line, or use your brakes too often and too forcefully, this can also result in air getting into your system.

Bleeding your brakes gets the air out of the system, and is a quick process. Unless you are a skilled mechanic, it is better to leave bleeding your brakes to the professionals. It can be difficult, and if you do not do it correctly, you can cause serious damage to your vehicle or the brake system. It is often performed if you are having routine maintenance performed on your vehicle, and should be done every two to three years.

Why Should You Bleed Your Brakes?

In order for your hydraulic brake system to work, there needs to be fluid that cannot be compressed. This helps the brake pedal tell the rotors that it is their time to shine. The fluid is basically the message your brakes need to kick into gear.

If air gets into the fluid, then you have a problem! Not only do you straight up not want air in there, but it can also have a negative impact on the message that your brakes receive from your brake pedal. This can damage your brakes, and even be a serious safety risk if you are not careful.

If you keep up with the regular maintenance on your vehicle, then you will have less of a risk of air interfering with your brake line. Replacing your brake fluid is also an essential way of keeping your brakes in working order.

You should have your brakes bled whenever you are replacing your brakes or your brake pads. If your vehicle has sat for a long time, then you will want to bleed your brakes because it is likely that air has found its way inside your brake line. If you drive a lot, then try and get your brakes bled every 24,000 miles, and even more often if you tend to be a heavy brake user while driving.

Why is Air So Bad?

Even if you only have a few small air bubbles in your brake line, it could get worse over time. A bunch of small ones can come together and form one large bubble. If a large bubble forms, it will cause the pressure to drop, and your brakes can fail entirely.

There is no reason to ever have air in the brake system of your car, and the quicker you resolve this problem, the better off you are going to be in terms of repair cost as well as your personally safety and the safety of your family as well. Even if you bleed your brakes like you are supposed to, air can still get into the system, which is why most people use mechanics to ensure that the process is being done properly.

How Do You Bleed Your Brakes?

When you take your vehicle to get the brakes bled, it is a relatively simple process for a mechanic to do. This is not only because it can be risky, but also because you will need someone to help you. Here is how a mechanic will bleed your brakes, and it is called the pump and hold method.

  1. Locate the brake bleeder nozzle located inside of the wheel.
  2. Loosen the nozzle with a small with a small wrench.
  3. With a piece of hose, place one end over the nozzle and the other in a container.
  4. Have another person pump the brakes of the vehicle a few times.
  5. With the pedal pressed down, slowly open the bleeder nozzle.
  6. With the pedal pressed, tighten the nozzle back.
  7. Repeat steps 4-6 until you have no more air bubbles showing up.
  8. Replace the brake fluid and repeat for each wheel if necessary.
  9. The last step is to test drive the vehicle before you set out on a journey.

While this is the most popular method, there are also other methods that you or your mechanic may choose to use. Many of these are more technical and require different tools that the average consumer may not have. With these methods, you may have to do them more than once to get all of the air out of your brake system.

  • Vacuum Pulled: Mechanics will sometimes use a vacuum as a way to get the air out of your brake system. There are some vacuums that come with attachments dedicated to brake bleeding. In order to use this method, the hose is simply attached to the bleeder nozzle, and then the vacuum is turned on. This is not always full proof as air can get around the hose and nozzle.
  • Pressure-Operated Venturi: This is actually another form of a vacuum system. It uses compressed air and a venturi, which causes expansion and compression of fluids to change the pressure inside. This method can also cause extra air to enter the brake line if you do not seal it correctly.
  • Pressure Tank: Most mechanics claim that this is the best method to bleed your brakes other than the pump and hold method. This is a great method to get every drop of brake fluid out of the system. This method requires the mechanic to check the tank to cylinder connection, depressurize, fill the brake fluid, and then pressurize.

Your Brakes May Not Bleed at First

If your brakes are in working order, then they should always bleed. There are a few reasons why your brakes may not bleed, and they can be serious problems. If the bleeder nozzle on your vehicle is blocked or rusted, then you are going to either have to them fully replaced or use heat to release the nozzle so you can get the fluid and air out. Another reason that your brakes may not bleed is that there could be so much air inside of the system. This can plug the hose so that the fluid is not moving inside of the system, or even the clamp holding the hose could be rusted and causing too much compression on your brake line.

Arwood

I'm Arwood, but the grandkids call me Big Papa. After retiring from teaching automotive classes for 30+ years I decided to create a blog about all the questions I used to get about brakes and anything automotive.

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