Audi A4 B8 A5 8T Brake Servo Booster Master Cylinder Module 8K0612103E

Audi A4 B8 A5 8T Brake Servo Booster Master Cylinder Module is an original braking system component from the Brake Servos and Proportioning Valves group, designed for use in mid-size Audi models. This used OEM component allows for maintaining factory braking characteristics, stable pedal operation, and predictable vehicle response during daily use.

Specifications and technical data

• SKU: 8K0612103E
• Mark: Audi
• Condition: Used
• OEM Part Number: 8K0612103E
• Substitutable numbers: 8K0612103E, 8K0 612 103 E
• Category: Brake Servos

Purpose and function in the braking system

The presented brake servo with master cylinder module is responsible for assisting the pressure force on the brake pedal and precise metering of pressure in the brake circuits. Thanks to the use of the original Audi design, the following are maintained:

• consistent brake pedal operating characteristics,
• stable assistance across the full load range,
• proper cooperation with other braking system components.

This solution is particularly important in vehicles of the Audi A4 B8 and A5 8T class, where the braking system must combine user comfort with predictable response during emergency braking.

Benefits of using the original servo with master cylinder module

Using a complete servo assembly with a master cylinder module instead of a worn-out part helps reduce the risk of improper braking system operation. Key advantages include:

• Factory fitment for the Audi braking system – no need for adaptations or modifications.
• Consistent cooperation with existing brake lines and equipment.
• Reduced risk of uneven braking resulting from mismatched components.
• Ability to maintain the original system operating characteristics, in accordance with the manufacturer's specifications.

Choosing a used OEM component is often a beneficial compromise between repair costs and maintaining high quality and predictability of the braking system's operation.

Product characteristics and condition

The offered component comes from the Audi brand and is classified in the Brake Servos and Proportioning Valves group. As a used part, it retains a construction consistent with the manufacturer's factory standards, which facilitates trouble-free installation in the vehicle. This type of part is particularly recommended in situations where the existing servo shows signs of reduced assistance efficiency, unstable pedal operation, or leaks in the system.

Before installation, it is recommended to perform a standard verification of the braking system and check other cooperating components to ensure even and safe operation of the entire system.

Installation and operational recommendations

Due to the importance of the braking system for safety, the installation of the servo with the master cylinder module should be performed by a qualified service center, following the manufacturer's procedures. In practice, this means, among other things:

• proper bleeding of the braking system after replacement,
• checking the tightness of connections and lines,
• verifying the brake pedal travel and operation after installation,
• a test drive in safe conditions to evaluate the system's response.

This approach allows for fully utilizing the potential of the offered component and maintaining stable, predictable braking in daily operation.

If you are planning a comprehensive repair or upgrade of the braking area in your Audi and need other elements from the same group, such as servos, proportioning valves, or related modules, check the available parts in the Audi Brake Servos and Proportioning Valves category.

For drivers who are also servicing the thermal comfort system in their vehicle, a guide on selecting and maintaining components responsible for air conditioning and heating may be helpful. Practical tips, comparison tables, and service procedures can be found in the article Air conditioning and heating – part selection and maintenance for year-round comfort.