Brake systems with four-piston calipers

Braking systems are one of the most important parts of any vehicle, ensuring the safety of the driver and passengers. One of the types of braking systems that are used in automobiles are four-piston caliper systems. They provide high braking efficiency, improving control and shortening braking distances.

Four-piston calipers are mechanisms that use four pistons to press the brake pads against the disk. Two of these pistons are located on each side of the disk, ensuring even distribution of braking force. This contributes to more stable braking, especially under high loads and heavy use.

Types

Fixed calipers: the body is stationary and the pistons are positioned on either side of the disk. This allows the pads to be pressed evenly against the disk, providing stable braking force.

Floating calipers: the housing can move relative to the brake disk. These systems typically use one or two pistons that press one of the pads against the disk, while the housing shifts to press the other pad.

The main differences between the types are

Fixed calipers have a complex design with a large number of pistons, making them more massive and difficult to maintain. Floating ones are simpler, lighter and more compact.
Fixed calipers provide more even braking power due to the multiple pistons, which is especially important for sporty driving and high loads. Floating calipers are less effective under heavy braking, but handle normal driving conditions quite well.
Fixed ones are more expensive to manufacture and maintain because of their more complex design and greater number of components. Floating calipers are cheaper to manufacture, making them more popular for mass-market cars.
Fixed ones usually have better heat dissipation ability due to more even heat distribution across the disk. Floating calipers can be less efficient in this regard, sometimes leading to overheating under extreme conditions.

The choice between calipers depends on the vehicle’s intended use, operating conditions, and brake system requirements.

The main components of the system

The brake disk is the main element that the brake pads act on when braking. It is made of high-strength materials that can withstand significant thermal or mechanical stress.
Calipers — components that ensure that the pads are pressed against the disk. They use four pistons, two on each side, which allows even distribution of braking force and provides more effective braking.
Brake pads are the elements that make direct contact with the disk, creating the friction necessary to slow and stop the car. They are made of friction materials that can withstand high temperatures and wear.
Brake hoses and lines carry fluid from the master cylinder to the calipers. The hoses are flexible and strong enough to withstand pressure and mechanical stress.
The brake master cylinder is the component that converts the mechanical force applied by the driver to the brake pedal into hydraulic pressure in the brake system.
A brake vacuum booster (if available) helps reduce the force required to depress the pedal by using vacuum from the engine to create additional pressure in the system.
Brake fluid is the fluid that transmits force from the master cylinder to the calipers. It must have a high boiling point and low viscosity to effectively transmit pressure in all conditions.
ABS is an electronic system that prevents the wheels from locking during hard braking. It consists of speed sensors, an electronic control unit and hydraulic modules that regulate brake fluid pressure, preventing lockup and providing more stable braking.

Features

The four pistons in the calipers are placed two on each side of the brake disk, which ensures that the brake pads are pressed evenly against the disk. This reduces the risk of disk deformation and improves braking performance.
By distributing the load more evenly and using more sophisticated designs, calipers often provide better cooling of the brake disk. This is particularly important in heavy use, as it prevents overheating and subsequent reduction in braking performance.
They are usually made of high-strength materials that can withstand high temperatures. This makes them resistant to overheating, which is especially important in high-stress environments such as motorsport or mountain operation.
By distributing braking force evenly and dissipating heat more efficiently, they provide more predictable and stable braking. This is especially important for sports cars where braking accuracy and reliability are critical.
Due to even pad-to-disc contact and better heat dissipation, pads and discs wear more evenly. This increases their service life and reduces the frequency of needing to replace these components.
Often fitted to sports cars and high-performance models where high braking performance is required. Their ability to provide stable braking under high loads makes them ideal for such applications.

Benefits

Uniform brake force distribution , which improvesbraking performance and reduces the risk of disk deformation.
Improved cooling maintains stable braking performance.
High resistance to overheating, especially important in intensive use.
More predictable braking, critical for sports cars.
Uniform pad and diskwear due to stable pressure reduces replacement frequency and extends component life.
Use in high-performance vehicles due to their ability to deliver high braking performance.

Disadvantages

Complex design, which can make them difficult to maintain and repair.
Higher cost due to complex design and use of high quality materials.
Heavier components, which increases the unsprung weight of the vehicle and can negatively affect handling and ride comfort.
More installation space, which limits their use in some car models, especially compact cars.
Brake fluid requirements that must be checked and replaced regularly, which adds additional maintenance costs.

Installation and maintenance

Raise the vehicle with a jack and securely fasten it to the jackstands. Remove the wheels to gain access to the brake system.
Remove the old calipers by unscrewing the retaining bolts. If necessary, disconnect the brake hoses and drain the brake fluid. Remove the brake disks and pads.
Inspect the new components for damage and contamination. Make sure that all necessary parts and fasteners are included in the kit.
Install the new brake disks on the wheel hubs. Secure in place using the appropriate mounting bolts. Connect the brake hoses to the new calipers, making sure there are no leaks.
Insert the new brake pads into the calipers, making sure they are properly seated and move freely.
Once all components are installed, the brake system must be pumped to bleed the air out. To do this, use special equipment or pump the system by hand, starting at the wheel farthest from the master cylinder and moving to the wheel nearest to it.
Check all connections for tightness and reliability. Make sure that the brake pads are properly pressed against the disks and do not create unnecessary resistance when turning the wheels.
Put the wheels back on the vehicle and lower it off the jacks. Take a test drive to make sure the braking system is working properly and there are no unwanted sounds or vibrations.

System Maintenance

Check the brake fluid level and condition regularly. Change it according to the manufacturer’s recommendations, usually every 1 to 2 years.
Periodically check the condition of the brake pads. Replace them when they reach the minimum allowable thickness or if they show uneven wear.
Inspect brake disks for wear, cracks or deformation. If necessary, replace or resurface the discs.
Inspect calipers and brake hoses regularly for leaks, damage or corrosion. Replace worn or damaged components as necessary.
When replacing brake components or if a soft brake pedal occurs, bleed the system to remove air.
Periodically lubricate caliper guides and pistons with a special lubricant to ensure free movement and prevent jamming.

By following the above recommendations, you can ensure long service life and high braking performance. If you have no experience with brake systems, it is better to contact professionals for installation and maintenance.