Understanding Brake Caliper Parts & Types

A vehicle’s braking system works with several components to successfully stop your car. One of which is the brake caliper. While not too known, like the brake pads and pedals, they are essential components of the braking system. So what is a brake caliper? The brake caliper houses the piston, pads, and other brake system components. Its task is to help slow down your wheels by generating friction with the brake rotors.

The caliper connects directly to a circular rotor. The rotor itself is attached to your car’s wheels and spins along with the wheels. When you hit the gas pedal, the brake fluid pressurizes the piston, pushing the brake pad against the rotor to slow down your car. The caliper, however, comprises different components that allow it to work effectively. But before we discuss brake caliper parts, let’s snoop into the types of brake calipers.

brake caliper components

Types of brake calipers

There are several brake calipers, but the two major types are floating and fixed brake calipers.

Floating brake caliper

Floating calipers, also called sliding calipers have pistons on only one side of the brake rotor, with brake pads on the other side. The pistons can be 1, 2, or 3. But basically, floating calipers work by combining one piston and two brake pads, with the piston placed near the inner brake pad.

It works by sliding back and forth on its bushings or pins that act as clamps or support. Here is how it works. As you hit the brake pedal, hydraulic pressure created pushes the pistons against the inner brake pad, which in turn pulls the calipers against the outer pad.

Hence, creating friction from both sides of the rotor to stop your car. Floating calipers are small, lighter, an inexpensive option and are commonly used on many passenger cars and light trucks today.

Fixed brake caliper

Fixed calipers have pistons on both sides of the rotor; the pistons can be 2, 4, 6, and even 8. And as the name suggests, they don’t move with the rotor moving, so they need fixed support. Hence, rigorously secured on the steering knuckle (caliper support). Fixed calipers basically work by combining two pistons and two brake pads.

As you hit the brake pedal, the hydraulic pressure generated pushes the two pistons, squeezing both brake pads against the rotors. Hence, creating friction on both sides of the rotor to stop your car. Fixed brake calipers are larger and work smoothly and efficiently, and so are commonly used on luxury and high-performance vehicles. They are, however, very expensive.

Other brake calipers

Brake calipers can sometimes be customized to match your vehicle’s performance.

  • Motorcycles fitted with disc braking systems usually require light brake calipers made from aluminum and use numerous pistons for support.
  • Larger trucks and SUVs used for towing can be fitted with aftermarket brake calipers for better braking performance and a customized look.
  • High-performance vehicles can also be outfitted with high-performance calipers. High-performance calipers, in many cases, use larger pistons and don’t retain much heat.
  • Another option is the differential bore caliper which combines large and small pistons for effective braking.

Brake calipers parts

The caliper comprises many parts that work together to help bring your car to a stop. So here are brake caliper parts and function.


The caliper houses the piston, pads, cylinder bore, and other brake components. It is made with either of these three materials— magnesium, cast iron, or aluminum.

Mounting bracket (Adapter)

The brake caliper bracket acts as a support to the entire caliper assembly and is usually connected to the hub housing. It harbors the whole braking weight.

Cylinder bores

The cylinder bore is the component of the caliper in which the piston moves. The cylinder bore comes in various sizes, and the caliper can use different numbers of cylinder bores. However, the size and number of cylinder bore in a caliper depend on the number of pistons and sizes.

Brake pistons

During braking, it is the brake caliper pistons that push the brake pads against the rotors to stop your car. How many pistons your caliper utilizes depends on the type of caliper. Usually, a fixed caliper uses more pistons than a floating caliper.

Generally, pistons come in different sizes–small and large, so which you use depends on the braking force. The braking force of one big brake caliper piston almost equals the braking power of two small pistons.

Pins and bushes

Pin and bushes act as a support to the caliper; the caliper practically sits on them. In a siding or floating caliper, the pins and bushes help the caliper move to and fro smoothly while keeping it in place.


In between the pins and bushes is the positioner. It assists in holding the caliper outward when the pedal is released so that the outer brake pad can detach from the rotor. It also serves as a brake pad wear indicator and becomes invisible when the brake pads are worn.

Dust boot

The dust boot, otherwise called the piston boot, acts like a filter. It restricts dust or other contaminants from entering the cylinder bores.

Retraction spring

Also known as a rattle ring, the retraction spring helps keep the brake pads in steady contact with the piston and caliper fingers.

Brake pads

The brake pad applies force to the rotor, which connects directly to your wheels. This force created helps to slow or stop your vehicle. Generally, as the rotor slows down, so do your wheels. It’s built of small materials with high friction. The type of friction material, however, depends on your vehicle.

brake caliper piston


What is the part that the brake caliper attaches to?

The brake caliper is attached to the steering knuckle through mounting bolts and partly connected to the brake rotor. The steering knuckle consists of wheel hubs and connects directly to the suspension and steering parts. It helps in transferring steering wheel movement to the front wheels.

What is the difference between floating and sliding caliper?

Floating and sliding calipers are the same; they are names just used interchangeably. A floating caliper, otherwise called a sliding caliper, has pistons on only one side of the rotor, with brake pads on both sides. Practically, both are built with the same materials and work on the same mechanism.

Can a brake caliper be repaired?

A brake caliper can be repaired. The issue is how much time you are willing to put into the repair. If it’s an issue of the slide pins/bolts rusting or sticking to the caliper, the repair process is pretty easy.

All you need to do is remove them completely and clean them with a rag and brake cleaner. After which, you lubricate with silicone grease or its alternative. Replace the slide pins if they show signs of wearing or look different compared to others.

And remember to buy the parts that match the current calipers. Brake caliper parts for Ford vehicles will work differently from motorcycle brake caliper parts.

What do brake caliper slide pins do?

The brake caliper slide pins support and help keep the caliper in place. It allows proper alignment of the caliper brake pad to the rotor and smooth movement of the brake pads under normal driving conditions.

However, these pins may seize if not serviced or lubricated regularly, especially if you drive on salty roads. In many cases, it’s better to change them if they get rust, as cleaning them is only a temporary solution. They won’t work for long before seizing up again.

Is it better to rebuild or replace brake caliper?

Generally, replacing would save you time, while rebuilding will save cost. But regardless of whether you’re saving time or cost, the severity of the damage matters. To rebuild, you would need a brake caliper repair kit which should contain brake caliper parts like the O-rings, necessary seals, and other hardware to do a caliper repairs.

While this kit is an affordable option, usually around $7-$15, there are some repairs they can’t do. For example, the kits do not have a piston, so if your piston is damaged beyond repair, you may need to replace the caliper instead. Likewise, if a caliper made of aluminum or cast iron or the cylinder bore is badly damaged, a repair kit won’t suffice either; replace the caliper.

Replacement, however, will depend on how many calipers you’re replacing; one caliper is usually allocated to each wheel. Replacement of all calipers may be about $400-$750, with labor around $75-$150 and parts estimated between $325 and $600. However, you’re more likely to carry out a front brake caliper replacement than a rear brake caliper since the front wheels do most of the braking.

What brake caliper type is most commonly used?

The most commonly used brake caliper is the floating, also called sliding brake caliper. They are common because they are inexpensive to manufacture and fix. If you’re rebuilding, floating brake caliper parts cost should be around $10 to $15. Floating brake calipers are light and portable, and you should find them on many passenger cars and light trucks.

Final Words

Brake caliper parts work collectively to enable you to brake effectively. This means that all must be in good shape if the brake caliper must function properly. If any part is malfunctioning, you should fix it immediately or replace it. A defective caliper may cause continuous brake squealing, squeaking, or grinding.

It could even cause the ABS warning light to come on, the car to pull one side during braking, a stiff pedal, and too much effort to push the pedal. However, the brake caliper is just one of the brake components; other faulty brake parts could also be responsible.


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