Bleed All 4 Brakes? (Changing Calipers, Bleeder Valves)

Brake bleeding is a concern among drivers as it affects their safety.  Fortunately, you can remove the air trapped in your brake fluid with brake bleeding and improve your car safety.

So, do I need to bleed all 4 brakes? Bleeding all four brakes in your car should be a common practice. Generally, when you change the caliper, your four brakes will bleed. However, if the brake line you intend to bleed has an independent brake system, you do not have to bleed all four brakes.

Bleeding is essential to your brake system and your overall car. Despite bleeding being important as a maintenance practice, you may not always want to perform the procedure on all four brakes at a go. I will help you know whether bleeding all your four brakes is necessary.

You do not need to bleed all four brakes in your car, but this should be a common practice. Ideally, when you change your caliper, your four brakes will bleed. However, with independent brake transmissions, you do not necessarily have to bleed all four brakes.

Before diving into bleeding all your four brakes, you need to tell apart an independent brake. Modern cars have independent brake lines, and it is easier to figure them out. To do this, inspect the ABS unit, and you will see the distribution lines marked with FL for Front Left, FR for Front Right, RR for Rear Right, and RL for Rear Left.

In an independent brake system, every wheel will have a dedicated brake line. Thus, you can bleed a brake caliper independently as long as the brake fluid is within the low-level mark in the reservoir.

Cars made in the last 20 years have an ABS with three channels, the front calipers with independent brake lines, and a pair for the rear ones. In such a system, your front calipers will be fine with independent bleeding, but the rear brakes require you to bleed them together. That is, brakes on the same line require bleeding together.

You should follow the bleeding sequence for the best results when bleeding your four brakes. Start with the brake line that is furthest from the oil tank. In most cars, the oil reservoirs are on the right rear wheel. If your car’s rear wheels have brake lines, you will start with the front wheels and move to the passenger seat and the steering wheel.

When bleeding your brakes, you will start by opening the bleeding valve. Opening the brake nipples is one of the most complex parts of the process. You can do this with a wire brush before putting a wrench on them.

While doing this, be careful lest you damage your valve knob.  You do not necessarily need a wrench, as the vice grips can be handy. Next, push the brake fluid through gravity, pressure, and vacuum. Once done, refill the system and close the bleed valve.

Avoid stepping down on the brakes more than halfway when bleeding your brakes. If you have a helper, ask them to step on the brake at least ¾ off the floor. Also, do not reverse the brake bleeding order, as this will make the process ineffective.

Changing a caliper without bleeding brakes?

Brake servicing is part of vehicle ownership, as your rotors and brake pads will wear out over time. When your calipers are damaged, you will need a replacement. Read on to understand whether you can change your caliper without bleeding the brakes.

You can change a caliper without bleeding brakes, but this may vary depending on the situation, the procedure used in changing the caliper, and the vehicle model you are working on. Removing the caliper breaks the seal between the caliper and brake hose, allowing fluid and air.  As you place the new caliper, you will need to reseal the hose connection to stop the leaking fluid. In the process, the system traps air. Given that air is compressible, but the liquid is not, the result will be spongy brakes, which are liable to fail.

Before changing the caliper, we must understand its function and interaction with your brakes.  Modern vehicles feature a complicated brake system. When you apply your brakes, you create a force and send it to the hydraulic system. Hence, the brake fluid will move to the wheels through the brake lines.

The force of this fluid will also push the brake pads, creating friction on the rotor and slowing your vehicle. The brake caliper in the above system is the meeting point between hydraulic and friction components. 

One or more pistons inside the caliper, depending on your vehicle’s needs, move against the brake pads when you apply pressure. It is then that the brake pads make contact with the rotors.

Unlike rotors and brake pads, calipers do not need a planned replacement. While they can last you for the duration you own your vehicle, certain factors will dictate that it is time to replace your calipers.

First, your vehicle may start pulling on one side. This usually happens with one brake engaged, causing a drag to one side. Secondly, a soft or spongy brake could indicate the time to replace your caliper.

You may also hear grinding or other abnormal sounds due to friction. A burning smell from the wheels can also alert you. Other signs include seized caliper pistons, slide pins, brake fluid leakage, or rust around the piston.

Once you confirm your calipers need replacement, you should do so in pairs for the best performance. Given that calipers are side-specific double-check your parts before installation. A bad caliper will amount to uneven brake pad wear; hence, having rotors and pads for both sides is essential. 

If you replace the pads alone, you need not bleed your brakes as these functions are unrelated.  In this process, you will remove the pads or the caliper piston, pushing the fluid towards the master cylinder. Given that you will not open the hydraulic system, bleeding is not necessary.

After changing the pads, the pedal usually feels like it needs bleeding, but this results from retracting the caliper piston to create room for the thick pads. To resolve this, pump the brakes several times to push the pads against the rotors. In the process, the pedals will become firm.  When pumping your brakes, avoid pushing the pedal to the floor. Instead, stop at about ¾ way down and pump at this level.

Bleed brakes without bleeder valves?

Brake bleeding removes air from the hoses and pipes in your brake lines, transmitting the brake fluid. These air bubbles reduce your brake efficiency and can damage major parts of your brake system. Hence, bleeding your vehicle brakes at regular intervals is advisable for optimum functionality. Among the parts necessary for effective bleeding is the bleeder valve, and I will help you know if you can still bleed your brakes without it.

You can bleed brakes without the bleeder valve. This is especially if your vehicle’s bleeder screws are rusty. To achieve this, use the gravity or pressure methods. This process is simple if you have a helper on the pedal as you work underneath your car. Still, if you are not confident, hire a professional to do the job for you.

Before proceeding further on bleeding your brakes without the bleeder valve, it is worth understanding that the bleeder valve is a screw component of your car’s braking system, usually on the brake caliper.

It aids in removing trapped liquid or oil from your brake line. As such, knowing how to bleed your brakes without this part is crucial should it wear out and you are not in a position to replace it.

As stated, you can adapt different bleeding methods for your car. These include gravity, vacuum, pressure, and the pump and hold methods. The method you select will depend on your vehicle model and recommendations from your mechanic. Once you decide on the method, wear protective gear to protect your skin from the corrosive brake fluid.

Start by ensuring that your master cylinder has enough brake fluid content for this process. The oil liquid should be within the full mark and not below, lest it drains out in the process. With this set, jack your car to a moderate level that will enable you to work easily under your car. Jacking your car safely is necessary to avoid risking your life should your vehicle fall.

With your vehicle secured, proceed to remove the wheels and crawl under the car to locate the bleeding screw. These screws are usually on each of the brake calipers. Next, loosen the screw using a wrench. If experiencing difficulty, apply grease, then remove the brake caliper from the wheel.

You can then use a pair of pliers to remove the brake caliper from the brake line. Insert the brake line end into a can with new or old brake fluid. This process will require you to have an assistant who will continuously apply pressure on the brake pedal as you monitor the fluid on the can.

With constant application of pressure to the pedal, the old brake fluid will exit from the system. You will also see air bubbles coming out of the system, and you should repeat this process until no more bubbles come out of the brake line. While doing this, ensure your master cylinder is full of the new fluid depending on your car.

The brake fluid should be of high quality. You can check its color to establish if it is original or counterfeit. A low-quality brake fluid will impact the system negatively. Afterward, remove the old brake fluid from your caliper and replace it with the new one.

After completing the above process, fix the brake line to your caliper and reassemble it to your vehicle system. While doing this, ensure the bleeder brake system is airtight. Also, avoid facing the caliper down as this will pour the brake fluid inside.  Repeat the above process for all the wheels.

While aiming at an airtight system, avoid applying too much pressure, as this can damage some parts. Once done bleeding, fix the wheels and tighten the wheel screws. Lastly, lower your car with the jack and refill the maximum cylinder to its maximum gauge with the new fluid.

Bleed brakes with a broken bleeder screw?

A bleeder screw is a necessary component in bleeding. Air will naturally or through compression rise to the top of the fluid inside the caliper. Loosening this screw removes the air from the system, and I will help you know whether it is possible to bleed brakes with a broken bleeder screw.

You can bleed brakes with a broken bleeder screw. To achieve this, use either the gravity or pressure bleed method.  Start with the brake nearer to the master cylinder. While doing this, ensure that the master cylinder is at its maximum. To change the old fluid, drain the fluid from the master cylinder and replace it with the new one.

While you can still bleed with a broken bleeder screw, this is possible if you can remove the broken one. However, if there is not enough material sticking out of the caliper, you will have to replace the caliper. If unable to do this, visit your nearest brake shop and have them replace it for you.


Bleeding your car brakes remains an important maintenance practice. Bleeding your four brakes at once should be common but not mandatory. Depending on your brake system, the four brakes will automatically bleed when you change the caliper. However, an independent transmission can dictate the lines you bleed.

You can also change the caliper without bleeding the brakes, depending on the situation. However, the latter will depend on your vehicle model. In most cases, you may need to bleed the brakes with the caliper change, as the system may trap air as you replace the caliper.

Finally, bleeding your brakes is possible without the bleeder valve or with broken or damaged bleeder screws. To achieve this, use the gravity or pressure methods. The process is much easier with a helper. Still, if you are not confident, consider a professional to do the job for you.

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