Audi A8 D4 4H Brake Caliper Front Left N/S Wheel Brake Unit 356X34MM 4H05BD

Visual condition of the part 

The product shows signs of use visible in the photos. 

Audi A8 D4 4H Brake Caliper Front Left N/S Wheel Brake Unit 356X34MM is an original Audi brand brake system component, designed for the front left axle of the vehicle. The robust OEM construction ensures stable brake pad guidance, even pressure on the disc, and predictable vehicle behavior during intensive braking. This is a solution for users seeking a proven, factory-spec caliper rather than random aftermarket replacements.

Specifications and technical data

• SKU: 4G0615123B
• Mark: Audi
• Condition: Used
• OEM Part Number: 4G0615123B
• Substitutable numbers: 4G0615123B, 4G0 615 123 B
• Location on the vehicle: Front, Left
• Category: Calipers & Brackets

Purpose and brake system compatibility

The presented caliper is designed for operation on the front left side of the vehicle, in a system with a large-diameter, increased-thickness brake disc. This setup is typical for more powerful versions of the Audi A8 D4, where the braking system must effectively dissipate heat and maintain stable parameters at higher speeds and with the vehicle's greater mass.

The factory mounting and guide geometry allow for correct positioning of the brake pads relative to the disc, which reduces the risk of the vehicle pulling during braking, uneven pad wear, or vibrations. As a result, the caliper works well with the stock brake master cylinder and assistance systems such as ABS or ESP.

Construction and operating characteristics

The caliper belongs to a group of components with increased body rigidity, which translates into a stable brake pedal feel and repeatable braking force. The design includes appropriate brake fluid flow channels and space for pistons of a specific diameter, allowing for precise pressure dosing to the pads.

In practice, this means:

• a confident, linear increase in braking force in response to pedal pressure,
• better resistance to overheating during dynamic driving,
• stable brake pad guidance within the caliper, reducing squealing and vibrations.

Thanks to its factory origin, the component maintains compliance with the vehicle manufacturer's requirements regarding operating pressures, piston travel, and compatibility with stock brake lines.

Benefits of using an original, used caliper

Choosing an original Audi brake caliper from the secondary market is a reasonable compromise between repair costs and safety. An OEM component is designed for a specific model and brake system version, ensuring it maintains the correct operating parameters without the need for system modifications.

The main advantages of this solution include:

• factory fitment to the hub, carrier, and brake disc,
• preservation of the original braking characteristics intended by the manufacturer,
• reduction of compatibility issues typical of random aftermarket replacements.

Before installation, standard service maintenance is recommended – checking the condition of working surfaces, seals, and guides, as well as bleeding the system after installation. This allows you to fully utilize the potential of the part and ensure the even operation of the entire system.

Professional selection and operation

To correctly select a caliper for a specific Audi A8 D4 configuration, it is worth verifying compatibility with the vehicle documentation and the parameters of the brake discs and pads used. It is crucial to maintain the consistency of the entire system – from the master cylinder and lines to the calipers and friction elements – to achieve predictable, repeatable braking in all conditions.

If you want to better understand how to safely use used brake system components and how to optimize service costs, read the article: Brake calipers under the microscope: how to choose original used parts and reduce brake system repair costs.

Expanding the Audi brake system

If you are planning a comprehensive repair or upgrade of the braking zone in your Audi and need other components from the same group, such as additional calipers, carriers, or brackets, check out the available parts in the Audi Brake Calipers and Brackets category.

By using components from the same design group, it is easier to maintain the technical consistency of the entire system, which translates into predictable vehicle behavior during braking, even pad wear, and stable operation of active safety systems.