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

No matter how much you take care of your car there are always some maintenance problems that can unexpectedly occur. What if your brake caliper piston won’t go back in? The brake piston calipers are located inside the brake calipers. They push the brake pads onto the rotors whenever the brake pedal is pressed.

Reasons Behind Brake Caliper Piston Won’t Go Back In?

The calipers move back to their original position as soon as the brake pedal is released. Brake pads need to be replaced whenever they are worn out and there is a good chance that you might have to face stuck brake pistons while replacing the pads. There are a variety of reasons why brake caliper pistons won’t go back in. Those reasons are mentioned below.

1. Brake Dust:-

Brake pads release dust when they rub against the rotors. Over time the pistons get covered with soot or dust and may get stuck.

2. Worn Out Brake Hose:-

Another reason why a brake caliper piston won’t go back in is because of a worn-out brake hose. Brake hoses handle a lot of pressure from the pressurized brake fluid and over time they start to break internally. The main functionality of the brake hose is to enable the effective flow of the brake fluid to the braking system and then back to the master cylinder.

3. Seized Caliper Piston:-

If your brake caliper piston does not compress, a corroded or seized caliper piston might be the reason. The brake caliper pistons can get seized when you leave your vehicle unused for several months. Rust or corrosion often limits the brake calipers from operating correctly. Any amount of rusting of the piston boot will affect the ability of the caliper piston to move back. When you use your car regularly, the chances of rusting are quite less. However, inactivity or driving it on rainy days can lead to corrosion, resulting in caliper pistons seizing.

4. Binding Brake Caliper:-

A binding brake caliper applies to the floating type of calipers that are installed in most cars these days. Usually, expensive and classic or limited edition cars have fixed calipers installed in them. The simple distinction between these two is quite crucial and straightforward. For the smooth movement of floating or sliding, bushings and pins are used within the caliper. To determine if you are facing this issue, you need to open and check the fluid reservoir and with the help of a screwdriver, proceed to push the brake piston downwards.

5. Incorrect Wind Back Procedure:-

Rear calipers do not easily get pushed inside, the piston has to be turned and pushed in. A simple wind-back tool is used to turn and simultaneously push the rear caliper pistons inwards. To retract the rear caliper you need to use the wind-back tool to turn and push the piston. Do keep in mind that some calipers turn clockwise and some might turn anti-clockwise so do not forcefully push them in the wrong direction. Keep turning and pushing till the piston fully retracts.

Hence, these are some basic reasons why the brake caliper piston won’t go back in.

How To Fix The Issue Of Brake Caliper Piston?

Step 1:-

You have to clean the dust with a soft brush, or a clean cloth, and your brake caliper pistons might go back in. However, you may have to apply a little pressure using a suitable clamp, or else they may not push back in because of insufficient pressure. Also, keep in mind that the front and rear brake caliper pistons have different mechanisms.

Step 2:-

Apply pressure on the piston using a screwdriver and if the fluid comes out of the valve and the piston starts moving then it is the brake hose that has decomposed. Changing the brake hoses on all the sides will be a suitable thing to do since all of them would have aged by that time.

Step 3:-

It is always advised to change the brake fluid every 3 years and make sure that the recommended type of brake fluid is being used to save from corrosion.

Step 4:-

The rear calipers incorporate the parking brake by fitting in a brake lever and cable to it. The manual brake needs to be released before following the removal method.

Step 5:-

You need to open the bleed nipple of the brake caliper. While opening the nipple, try pushing on the piston using a screwdriver. If fluid comes out from the bleed nipple and the piston can retract, the brake hose is at fault.

Hence, these are some steps through which you can solve the issue of your brake caliper piston.

Following these are some necessary precautions which you need to take:

You should always exercise the necessary precautions while working on the brakes. Don’t leave the brake caliper hanging as it strains the brake lines.

Always makes sure that the brake fluid does not come in contact with the car’s paint as it can damage it and never leave the brake fluid reservoir open for long since it absorbs moisture.

If you are installing new brake pads make sure that you have loosened the bleeder valve, doing so will release excess fluid out of the system.

A closed bleeder valve can create problems in the ABS unit because of the high pressure created by pushing the pistons back. Last but not the least, use a suitable clamp to push the pistons back otherwise they might get damaged.

What Is The Cost Of Fixing The Brake Caliper Pistons?

When there is a need of replacing the pistons, you will incur some costs. But the cost to fix the caliper piston issue will depend on several factors, such as the type of vehicle, the model of your car, and local labor charges.

Therefore, you can opt to restore your brake caliper using new seals and a piston. However, it is always a better option to get a new caliper. This can help you lower your overall costs.


We hope the above-mentioned information about the brake caliper piston won’t go back in and will be helpful to all the readers. If anybody’s doubts persist feel free to comment in the comment section below. We’ll try to solve your doubts as soon as possible.

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