What To Do If Your Brake Caliper Piston Won’t Go Back In?

Having fully functional and in excellent condition, brakes make all the difference and discovering that your brake caliper piston is not retracting can be discouraging. Imagine doing normal maintenance work, while changing your worn-out brake pads suddenly your brake caliper piston won’t go back in.

You’re bound to run into some servicing troubles, no matter how much effort and money you invest into keeping your vehicle. On the other side, impulsive decisions can complicate things.

Rather, while finding the source of the problems, you must exhibit patience and tranquilly. It will be simple to fix once you have identified the root cause. One such issue is the brake caliper piston’s inability to retract. Brake pistons can become stuck for a variety of reasons, which are listed below:

Why Your Car Brake Caliper Piston Won’t Go Back In?

The brake calliper piston is found within the brake callipers. The callipers are in charge of pushing the brake pads against the rotors when the brake pedal is applied. The callipers normally revert to their original position after the brake pedal is released. Here are some of the reasons why it will not return:

1. Corrosion

Corrosion is one of many car components’ worst enemies, and it can also cause brake pistons to freeze. Brake fluid is hygroscopic by nature, and it can absorb a lot of moisture from the atmosphere over time, corroding and eventually freezing the internal components of a braking system.

As a result, it is always recommended to change the brake fluid every 50,000 kilometers or three years (whichever comes first) and to use the recommended type of brake fluid.

2. Dust From Brakes Pads

When brake pads rub against the rotors, they release dust/soot, which coats the pistons and causes them to become stuck.

The cure is simple: easily take the dust off your brake caliper pistons with a gentle brush or a piece of cloth, and they should return to their normal position. You may need to have a little pressure with a proper clamp, or they may not push back in due to lack of proper power. Keep in mind that the mechanisms of the front and rear brake caliper pistons are different.

3. Wind Back Procedure Is Incorrect

If you’re working on a rear caliper that won’t retract, make sure you’re using the correct service procedure. Front and rear calipers are not the same and require different techniques.

Rear calipers are difficult to push inside because the piston must be turned and pushed in. A simple wind-back tool is used to turn and simultaneously push the rear caliper pistons inwards.

4. Piston Deformity

Your piston may be slightly misshapen or bent, causing it to stick and not compress fully. Any slight bend or deformity in the brake caliper piston could cause snagging or catching.

What Should You Do If Calipers Won’t Go Back?

When your brake caliper piston won’t move back in, it’s critical to address the issue right away. If the brake caliper pistons are not operating fine, brake failure might result. As a result, you may find yourself in a very dangerous situation. As a result, resolving the problem as soon as possible is critical. Here are some of the steps to perform to solve the problem:

1. Piston Cleaning

Clean the pistons to remove corrosion and buildup. This is a quick fix for a caliper piston that isn’t compressing properly, and it could be your first choice before spending money on other options. Channel locks can be used in the same way as the C-clamp. Place one end of the channel locks behind the caliper and the other behind the pad. The caliper and brake pad should be in the middle of the grips.

When you squeeze the channel together, the piston is compressed as well. Start slowly and gradually increase the pressure as needed.

2. Provide Prompt Maintenance

Because brake fluid was not refilled and brake pads were not replaced promptly, the brake caliper piston frequently developed problems. Taking good care of your brakes can help you avoid caliper piston problems.

3. Using C-Clamp

Place the C-clamp over the caliper and up to the piston’s end. On top, there’s a screw that needs to be adjusted properly. To protect the piston surface from damage, you should use wood.

The pressure increases as the screw are turned, allowing the piston to be compressed. Tighten until the caliper is compressed to the desired level.

4. Using A Screwdriver

A caliper piston can often be compressed without the use of any special tools. A standard screwdriver might be sufficient to complete the task. In the caliper window, insert your screwdriver. As you fit it into the openings, you must hold it tightly. The screwdriver must be dipped until the force balance is equal. The brake piston should pull back slightly as a result of the pulling motion.

Pull back slightly once the screwdriver is in place. You want to apply firm pressure to the pad in an outward motion. Your screwdriver can now be inserted between the piston and the brake pad. You should be able to gently push the piston back from this point.

Frequently Asked Questions:

Here are some of the frequently asked questions about brake caliper piston:

1. Why Won’t My Caliper Piston Return To Its Original Position?

The solution is simple: simply clean the dust with a soft brush or a clean cloth, and your brake caliper pistons may return to their original position. However, you may need to use a suitable clamp to apply a little pressure, or they may not push back in due to insufficient pressure.

2. Why Can’t I Get My Brake Caliper To Compress?

When the caliper piston won’t compress, it’s most likely due to a corroded or rusted caliper piston caused by a bad piston boot. Consider the possibility that the incorrect wind back procedure is being used if it’s the rear caliper piston.

3. Should The Bleeder Valve Be Opened To Compress The Piston?

The bleed screw does not need to be opened to compress the pistons. I use a brake pad across both front pistons and very large channel locks. The single rear piston does not require a pad. A large C clamp can also be used.

4. What Is The Cost Of Repairing A Seized Caliper?

If you use one of our tips to compress the caliper, you may not need to replace it. Every circumstance is unique. rdxszC8 brake hose could be causing the same symptoms, indicating that the caliper piston is still functional.


When working on the brakes, you should always take the necessary precautions. The brake lines will be strained if the brake caliper is left hanging. If none of the methods above work when the brake caliper piston won’t go back in your brake calipers will need to be replaced. They can be costly depending on the car model, which is why regular maintenance of a car’s braking system is always recommended.

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