Do You Have To Bleed Brakes When Changing Calipers?

When you are doing brake repairs, changing your calipers is an important step. But do you have to bleed brakes when changing calipers too? Let us find out!

Bleeding brakes is a crucial step and may not be as easy as it appears. We all have heard umpteen advice about bleeding the brake system when maintaining our brakes. The same is to remove any trapped air from the brake lines. It is natural to have multiple questions surrounding the same. In this article, we will answer do you have to bleed brakes when changing calipers and also look into some deciding criteria which can help you figure out when is the correct time for you to bleed the brakes.

Before we begin, we would also want to emphatically mention that what you will read in the following lines is not written concerning racing cars. Automobile experts are the best person to seek advice on them.


Do You Have To Bleed Brakes When Changing Calipers

When Should You Bleed Your Brakes?

Bleeding the brake system is not normally required. In their blog post, the Toyota Parts Center chalks out four to five situations where bleeding of brakes is typically required. 

1. Worn-out brake pads 

Completely worn brake pads affect the quantity of brake fluid in the master cylinder. The air gets into the brake system when this level drops way too much. 

2. Compressed Caliper Piston

One might need to open the bleeder valve to compress the piston when changing brake pads. Owing to this, air can enter the brake lines.


Do You Have To Bleed Brakes When Changing Calipers

3. Drum Brake Cylinder or Disc Brake Caliper Replacement

Both drum brake cylinder and disc brake caliper replacement call for disconnecting the brake lines. When the same happens, air may enter the brake lines. 

4. Replacement of other brake system components

Disconnectivity of any hydraulic part within the brake system causes air to enter the brake lines. 


You might also like to read: Do I Have To Bleed Brakes When Changing Pads?


What Happens if You Don’t Bleed Your Brakes After Changing Them?

When the brakes in your vehicle are not bled, the force from the brake pedals compresses the air and not the brake fluid. Because of the same, you may experience less responsivity in your vehicle brakes. 


These are often termed soft or spongy brakes, and one may notice the longer stopping distances taken by the vehicle when coming to a halt. This may worsen in some situations where the brakes could entirely fail. 


When you experience similar signs with your vehicle, it likely signifies air in your brake system, which means flushing the brake fluid is needed.  


Do You Have To Bleed Brakes When Changing Calipers

Do You Need To Bleed Brakes When Changing Calipers?

When brake calipers are changed, the brake lines are disconnected. This leads to the air entry of air into the brake lines that need to be removed, or else the brakes will become spongy.

After opening one brake line, it is a fairly common practice to bleed all four brake lines. However, one does not need to bleed the whole system after replacing one caliper as long as one uses some form of pinch clamp that prevents the fluid from gushing out of the master cylinder via the open brake hose. 

Also, if the brake line that has been opened happens to be independent, bleeding all four brakes is not required. 

If you have used a brake hose clamp, you must consider bleeding brakes. Let’s face it, changing the caliper is a tricky process. So one must refrain from doing so on their own, especially when one hasn’t done it before, or seek help from a professional to carry the process out. 

Just missing those copper washers on the brake line can cause pressure loss in the hose and cause brake failure. 

Changing the caliper does not necessarily require changing the brake pads. One may take off the brake pads if they are not worn out. As soon as you remove that banjo bolt on the top connecting the hose to the caliper, you lose the system’s pressure. 

This is precisely why bleeding them back is very important; the fluid will start leaking from the hose, and the reservoir level will drop.


You might also like to read: When Do You Need To Bleed Your Brakes? 3 Ways To Bleed Your Brakes Correctly


How Do You Bleed Brakes After Changing One Caliper?

Bleeding brakes can be fairly easy too and fairly difficult too. It depends on numerous factors. For example, cars that do not have ABS systems are generally fairly easy to bleed. 

Cars with ABS brake systems can be difficult to bleed in situations where the air has entered the ABS modulator. If you face difficulty doing the same, you must reach out to a repair shop that will use a scan tool to bleed your brakes. 

Some vehicles cannot be bled at home since their ABS systems have their valves positioned such that one cannot bleed them until a scan tool is used. Hence, before beginning with the bleeding process, one must have those mentioned above emphatically figured out to be clear if they can bleed the brakes at their home or they will have to drive to a shop. 

Step 1

Use a new washer when connecting the hose to the new caliper. Ensure the pistons are compressed and fit in place; use thread locking gel to prevent nuts from coming off due to vibration. 

Step 2

Now that everything’s in place, it’s time to bleed the brakes. Assuming you do not have a power bleeder, it still can be done by the gravitational bleeding method. This means to push out the air the new caliper pistons have and fill it with brake fluid

Step 3

Open the bleeder valve. Usually, it’s a two-person job to bleed the brakes, or you can make a brake bleeder tool. Open the brake fluid reservoir to properly flow and pump the brake pedal until you see clear brake fluid containing no air bubbles. 

Don’t let the reservoir level drop below the minimum while doing this, or you will be pushing more air into the system. Tighten the bleed valve and clean the caliper as the brake fluid is super corrosive so that it can damage rubber or paint. 


Do You Have To Bleed Brakes When Changing Calipers

Step 4

Top up the brake reservoir to the maximum marked level with fresh recommended brake fluid ( DOT 3 or DOT 4 ). Do not use old brake fluid since any debris can cause hydraulic lines to chock.

Moreover, brake fluid tends to absorb water over time, further the risk of damage to brake components. Hence, it is highly recommended to flush the brake fluid each time you change the brake rotors. 

Step 5

Try pumping your brakes, and if you feel like they are soft or go to the floor, you didn’t bleed them right. Bleed them again until the brake pedal feels firm. Install the brake pads with new anti-rattle clips if possible. 

Missing those clips will cause the brake pads to rattle, generating inadequate bite force and uneven force distribution on the disc.


You might also like to read: No Brake Fluid To Rear Brakes When Bleeding: 6 Reasons Why This Happens


A Few Final Words

We recommend bleeding brakes when you get the brake calipers changed. However, if the brake line opened is independent, then one does not need to bleed all four brakes. 

Also, if you still find yourself stuck and confused, you always have the option of reaching out to a car mechanic and getting all their doubts cleared. Thanks for reading until the very end. Give us a shoutout in the comments if we managed to answer your question. Also, let us know what more articles you want us to write. 


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Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

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