Brake Caliper Piston Buyer’s Guide
- A brake caliper piston is the part in your disc brake that is clamped over the rotor and attached to the brake pad.
- When the brake is applied, the brake caliper piston pushes the brake pad into the rotor to slow down or stop the wheel.
- A brake caliper piston usually has a long service life since it’s built to withstand the wear and tear that comes with its job.
- Once you notice that your car feels slow and it pulls to one side or you smell your brakes burning, it is high time to have your brake caliper piston checked.
- You may want to purchase a replacement brake caliper piston that has superb quality and matches the specifications of your vehicle.
- The price of an aftermarket brake caliper piston ranges from $10 to $210.
Slowing down or completely stopping your vehicle is no easy feat. This action can put so much strain on your braking system. That is why brake components are replaced on a regular basis.
When brake components wear out, you need to replace them as soon as you can to ensure that your vehicle’s braking power won’t falter. Otherwise, they won’t be able to slow down or stop your vehicle, which can jeopardize your safety on the road. One of the most important parts of your car’s braking system that you need to change when it gets broken is the brake caliper piston.
What is a Brake Caliper Piston?
The brake caliper piston is a crucial part of your vehicle’s disc brakes. It is clamped over the rotor and bonded with the brake pad. Brake caliper pistons can be found on both floating and fixed calipers. Floating calipers have one or two caliper pistons on the inboard side of the rotor, while fixed calipers can have as many as six pairs of caliper pistons on each side of the rotor.
How Does the Brake Caliper Piston Work?
When you press on the brake pedal, the brake fluid from the master cylinder generates the hydraulic pressure needed by the pistons in the brake caliper. This forces the brake pad against the rotor, which slows it down or stops it from rotating. When the brake rotor stops, the wheel and the vehicle also stop moving. Once you take your foot off the brake pedal, both the brake caliper piston and brake pad disengage.
How Long Does a Brake Caliper Piston Last?
Disc brake components often have superior durability to endure the wear and tear that comes with their function. This holds true for the caliper piston. It is designed to provide a long service life and may not require replacement for several years. However, with exposure to outside elements as well as the excessive heat produced by braking, it can prematurely fail. When that happens, a replacement becomes necessary.
Signs that You Have a Bad Brake Piston
All of the parts of your vehicle’s disc brake needs to be in good working condition all the time. When a component like the brake caliper piston fails, it can render your brakes ineffective. To prevent the worst from happening, you should look out for the symptoms of a failing brake caliper pistron:
Car feels heavy and slow
If you are coming from a full stop or from parking your vehicle, you may feel that the car is slow or heavy. This could potentially be due to a faulty brake caliper piston.
The piston may be stuck, so the brake pad is still in contact with the rotor. Hence, you are running while the brake is still applied. To solve this problem, you need to have a professional mechanic check your brake caliper piston and see if it needs to be repaired or replaced.
In some cases, the boot that protects the piston gets damaged and the residue gets stuck inside the caliper. This may cause the brake caliper piston to break down.
Car pulling to one side when running
Another sign that your brake caliper piston is faulty is when the car pulls to one side even though you are not moving the steering wheel. The piston might be stuck in the brake caliper, which causes the vehicle to move to one side when you are not applying the brakes. To avoid this problem and prevent situations wherein your safety will be put at risk when you are driving, make sure to make the necessary repair or replacement before you get back on the road.
Smell of burning brakes
When the brake caliper gets stuck because of a faulty brake caliper piston, the brake may generate high temperatures and produce a burning smell. This can be very dangerous, so you need to stop your vehicle once you notice this odor.
The extreme heat can cause severe damage to your brake discs and the other car components that are attached to the wheel hub. It can even start a fire. So before the problem gets out of hand, it is better to get your vehicle serviced by your trusted mechanic or auto repair shop.
Corroded brake caliper piston
The location of the brake caliper piston, which is close to the ground, exposes it to harmful contaminants like dust, dirt, moisture, and snow. Aside from these, the brake dust coming from the brake pads and rotors can also get stuck on the brake caliper piston. These contaminants can accumulate and speed up the corrosion of the brake piston.
What You Should Look for in Your Brake Caliper piston replacement
It’s not a good idea to skimp on your replacement car parts, especially if it’s a brake component. To ensure that you have excellent braking power when you are on the road, choose a brake caliper piston with top-notch quality. This will give you peace of mind that the component can serve a long service life and deliver superb performance.
If the replacement brake caliper piston that you have purchased doesn’t match the specifications of your vehicle’s make and model, it won’t be able to fit into your brake discs. That said, you need a component that directly replaces your factory-installed part to ensure a seamless fit and easy installation.
How Much is an Aftermarket Brake Caliper Piston?
Typically, the price of an aftermarket brake caliper piston falls anywhere between $10 and $210. You can purchase this part as a single component, in sets of four or six, or as part of a kit. It is also available in heavy-duty materials, such as phenolic plastic and steel or aluminum. If you want to have good consumer protection, make sure to buy a brake caliper piston that comes with a product warranty.
Having a Brake Caliper Piston Problem? Here’s How to Fix It
A broken brake piston is a common cause of disc brake malfunctions and should be immediately be taken care of, especially if the brakes are no longer functioning. And if you're planning on fixing a brake caliper piston by yourself, you need to do so at a slow and methodical pace to ensure that no mistakes are made during the process. So take your time and be sure to follow the steps below.
Difficulty level: Moderate
What you'll need:
- Piston repair kit
- Car floor jack
- Tire iron
- Ratchet set
Brake caliper piston removal tool/air hose
Step 1: With the car parked on a stable and level surface, engage the parking brake and raise the vehicle using a floor jack. Once it's lifted off the ground, place jack stands on your vehicle's designated jacking points and remove the jack.
Step 2: Remove the lug nuts with a ratchet or tire iron. You can also loosen them first before raising the wheel for added leverage, but make sure not to completely remove the nuts from the threads until the wheels are in the air. Once the nuts have been taken off, pull out the tire from the wheel hub and place it on the ground face up.
Step 3: Detach the brake pads from the caliper by removing the retaining clips. Use a vise grip to loosen the clips and slide out the pads.
Step 4: Have some press on the brake pedals, which will force the calipers to expose the brake pistons.
Step 5: Remove the piston from the brake caliper one at a time. You can use a special removal tool for this, although you can also use a pressurized air hose. For the latter, hold one piston with a C-clamp and blow out the other one using the hose. Wrap the caliper in rags to absorb any brake fluid sprayed out by the pressurized air.
Step 6: Clean out the inside of the caliper, the brake disc, and the brake pads. We also recommend putting an oil pan below the caliper and letting the escaping brake fluid drain into it.
Step 7: Inspect the piston for signs of damage and wear. Scrub off any dirt and rust and replace any worn cylinder seals, dust boots, and retainer pins. However, if the piston itself shows signs of cracks or fissures, it is no longer safe structurally and must be replaced completely.
Step 8: With the pistons cleaned and its seals and pins fixed or replaced, slide the pistons back into the caliper. Take note that the piston must be properly oriented with the rotor.
Step 9: Reattach the brake pads. The pistons need to be pushed into the brake rotors in order to slide the pads in, so either have someone step on the brake pedals again or compress the brake caliper with a C-clamp in order to slide the pads back into place.
Step 10: Return the tire to the wheel hub and secure it with the lug nuts. Lower the car gently into the ground.
Step 11: Refill the brake fluid reservoir and test your brakes. Take note especially of a spongy feel of the pedal; this means air has contaminated the brake pedal and must be bled out.