When Do You Need to Bleed Brakes? Your Ultimate Guide!

The brakes are considered as one of the most important safety features of your car. So maintaining it properly should always be one of your top priorities. One of the maintenance or services done to your brakes is brake bleeding. It is the process of pushing fluid through a hydraulic brake system to remove all the air bubbles. You might have asked, when do you need to bleed brakes, at some point. To answer the question, experts are recommending that you should have your car brakes bled for every two to three years.

However, the answer to the question, “when do you need to bleed brakes?” can vary at times. There are some situations that will call for a brake bleeding. Bleeding the brakes will be needed if the brake pads are completely worn, when the drum brake cylinder or disc brake caliper is replaced, when some of the other brake system components are being replaced, or when the caliper piston is compressed. But why is it important to bleed your brakes? Read on, we’ll tell you everything you need to know!

When Do You Need to Bleed Brakes? – Is it Important to Bleed Brakes?

If you have asked, when do you need to bleed brakes before, it means that you have heard about this certain maintenance. But what is it and why is it important? Bleeding a brake is one of the routine maintenance that needs to be performed over the life of a car. It is a maintenance procedure that should be done to a car on a regular basis to make sure that it will operate safely.

This maintenance is a common procedure. Bleeding the brakes is done to remove air from the car’s hydraulic brake system. Its process includes opening a valve to let air and some brake fluid to drain under pressure. But why does this air get into the brake system and why does it need to be removed?

To understand why bleeding the brakes is important and we need to ask, why do you need to bleed brakes, we need to know some basics of brakes and how they work. When you place your foot on the brake pedal, a hydraulic pump will put pressure against the hydraulic oil or brake fluid inside a number of tubes and hoses, which is also known as the brake lines. Since a liquid can’t be easily compressed, force will be applied to the fluid at a brake line’s one end which will be felt at the other end. As you step on the brake pedal, the pressure is applied by way of the master cylinder, through the brake lines, then to a brake caliper, which is a clamping mechanism on the other end.

This brake caliper works by suspending a pair of brake pads on each side of a metal disc or brake rotor. This brake rotor spins with since it is attached to the car’s wheel and tire. When the caliper squeezes the brake rotor, it causes friction which will slow and stop your car. So how does air get within the brake line and be trapped?

Small amounts of air tend to become trapped within the brake line over time. This can happen when the brake pads are severely worn or when the brake pads are not properly serviced, since they would allow air to enter into the system. Bad driving habits can also result in air entering into the brake lines, especially if you are constantly slamming on your brakes. Fluid leaks somewhere in the system can also cause air to enter. This can happen when the brake lines are damaged due to corrosion and some other issues.

If you ask,  is it important to bleed brakes? Regardless of the reason why or how air reached into your car’s brake system, it is important to have your brakes bled to make sure that your car is always safe to drive. Air trapped in your system can result in spongy brakes or a brake pedal that needs to be pressed all the way to the floor before it can be engaged. If this happens, it can compromise your safety since you won’t be able to apply the brakes fast, when you need to. Plus, if there is too much or large amounts of air in your brake system, it can lead to a complete braking failure.

When Do You Need to Bleed Brakes? – How Do You Know If You Need to Bleed Your Brakes?

When do you need to bleed brakes? You will know if your brakes are due for a bleeding when you experience any of these problems.

• Brakes are too soft.

When your brakes have air in it, you may notice that your brake pedal feels softer than it usually does whenever you step on it. You may feel that there is no resistance against your foot when you press it down.  It can also happen that you will have to push it further down to the floor before you feel the brake engage. Sometimes, you will lose the resistance completely and you will have to floor the brake pedal before your brakes work and slow down your car.

• Brakes feel spongy.

A healthy brake pedal feels even and smooth when you step on it. However, if there is air in our brake system, you may notice that your brake pedal feels spongy when you depress it. You may notice that the pedal feels like it is dragging instead of just smoothly going down when you apply the brakes. When you step on the brake pedal, it might have a bit of a bouncy feel which was not there before. When you notice this problem, it can be an indication that your lines or hoses have air in them.

• Brakes need some pumping to work.

You can pump your brake pedal several times if your brakes feel spongy or soft. This way, you can confirm if you really have air bubbles in your brake system. Doing this might not correct the brake issue, but it can help push the air pocket trapped through the system. If by doing this your brakes tend to work fine again, then it means that you really have air pockets or bubbles in your system.

There are times that pumping your brake pedal with much effort is the only way for you to be able to slow down or stop your car completely. This can happen when there is a large amount of air in your brake system since it can keep your brake pedal from getting the right pressure it needs to function properly. If this is the case, you will have to pump  the pedal aggressively to push the air bubbles in order to hit the pockets of fluid, for you to be able to stop your car.

When Do You Need to Bleed Brakes? – How Often Should I Bleed My Brakes?

When do you need to bleed brakes? Experts are recommending that you should have your brakes bled every 2 to 3 years to make sure that they are always at their top condition. However, there are some instances that call for a brake bleeding before the set interval. You will have to bleed your brakes when:

• Your brake pads are completely worn.
• You had your disc brake caliper or drum brake cylinder replaced. A brake bleeding is needed since replacing these components requires disconnecting the brake lines which will allow air to enter into the system.
• Some of your other brake system components are replaced.
• You have your piston compressed while changing your brake pads.

When you have your brakes bled, it will usually cost you between $80 and $100. If you want to save some bucks, you can do the brake bleeding yourself. However, in some vehicles, it can be very difficult to perform one. The level of difficulty can vary depending on some factors such as:

• If your car has an ABS system or not. If your car has no ABS system, it can be easy to bleed it. However, most cars with ABS systems can be bled easily if there is no air in the ABS modulator.

• If air has found its way into the ABS modulator, some brake systems can be bled easily but other vehicles may need to be taken to a shop since a scan tool will be needed in order to bleed the brakes.

• If the ABS system will require a scan tool to be bled and you have this scan tool, you may be able to bleed the brake system. You just need to make sure that you know how the valves should be positioned in order to bleed your system. You can do this by using the scan stool’s program which cycles the ABS modulator valves.

When Do You Need to Bleed Brakes? – Does Brake Bleeding Sequence Matter?

You already know the answer to the question, “when do you need to bleed brakes?”. But there is also another thing that you should remember, bleeding brakes should be done using the proper sequence. The experts are recommending it. If the proper sequence is done, you will be able to save time and make sure that your entire brake system will be bled.

The proper sequence in brake bleeding should be followed. It is advised that you check your owner’s manual and look for its bleeding sequence instruction since it can vary from vehicle to vehicle, but the process is usually done in the following sequence:

• You need to always start with the caliper or drum farthest from the master cylinder.
• Then work your way back to the closest one.
• You also need to make sure that you top off the master cylinder from time to time to prevent it from running dry.
• The sequence should be right rear, left rear, right front, and left front.

When you are bleeding your brakes, it is important that you should not force the brake pedal down more than halfway. If you force it, it is most likely that the master cylinder’s secondary piston will be driven through debris which was collected on the piston cylinder walls. If this happens, you will have to purchase a new master cylinder after bleeding your brakes since a replacement will be needed.

There are four common methods you can use when you want to have your brakes bled – the gravity bleeding, manual bleeding, pressure bleeding, and vacuum bleeding.

• Gravity bleeding – This method is done by simply allowing the fluid to run down into the calipers and wheel cylinders. To do this, you just have to place a container under the bleeder screw, open the said screw, and allow the gravity to take over. It will draw the old fluid into the container you placed under the screw.

• Manual bleeding – This is the most commonly used method. It can be done by using the master cylinder and brake pedal as a pump to allow the fluid to flow through an open bleeder screw. To perform this, you will have to ask someone to slowly push and release the brake pedal to force the fluid and air out. When doing this method, you need to work on the brakes as smoothly as possible so you won’t create more air bubbles that may contaminate your new fluid. You will know if you have created new air bubbles when the fluid coming out from your system is foamy.

• Pressure bleeding – This method uses a pressurized tank of brake fluid to allow the fluid to flow through the bleeder screw. This is known to be an effective method in removing air and flushing the hydraulic circuits.

• Vacuum bleeding – This method uses a pump to pull or draw fluid and air out of the bleeder screw. To do this, you will have to attach a vacuum bleeder to the bleeder screw when you open it.

Hopefully we have answered the question, “when do you need to bleed brakes?” and more in this article. It is an important routine maintenance that should be done at the right interval, or when you are having some brake problems or when you are replacing some components of your brake system. It is something you don’t want to ignore or delay since any problems with the brakes can compromise your safety.