Audi A5 S5 8T Brake Servo Vacuum Pipe Hose LIne Return Valve 8K0611931BC

Audi A5 S5 8T Brake Servo Vacuum Pipe Hose LIne Return Valve is an original brake system component responsible for the stable delivery of vacuum to the brake servo. Thanks to its factory geometry and integrated non-return valve, it ensures proper brake booster operation and predictable brake pedal response. This solution is intended for users who expect compliance with Audi's factory specifications and wish to maintain the integrity of the entire system.

Specifications and technical data

• SKU: 8K0611931BC-1
• Mark: Audi
• Condition: Used
• OEM Part Number: 8K0611931BC
• Substitutable numbers: 8K0611931BC, 8K0 611 931 BC
• Category: Vacuum Pumps

Function and role in the brake system

The presented vacuum pipe operates between the vacuum pump and the brake servo, responsible for maintaining the appropriate vacuum level during driving and sudden braking. The integrated non-return valve stabilizes the flow, limits vacuum backflow, and helps maintain repeatable booster force even during short, dynamic pedal applications.

A properly selected pipe with a non-return valve minimizes the risk of:

• loss of brake assistance during sudden braking,
• uneven servo operation,
• leaks in the vacuum circuit.

Construction and fitment for Audi A5 / S5 8T

The component has been designed specifically for the Audi A5 / S5 8T platform, which translates into proper routing of the pipe in the engine bay and a secure connection to the servo and vacuum pump. The factory design ensures:

• original-compliant pipe routing,
• stable mounting in brackets and sockets,
• proper cooperation with the stock brake servo.

As a result, installation is predictable, and the risk of stress or rubbing against other engine bay components is limited. This is particularly important in vacuum systems, where any leak can affect braking efficiency.

Component condition and service application

The vacuum pipe with a non-return valve is a dismantled part offered as a used item, which represents a reasonable compromise between cost and maintaining original Audi specifications. This type of component is suitable both for standard replacement of a worn pipe and for repairs after a collision or interference in the engine bay, where the factory vacuum line may have been damaged.

Choosing an original pipe from the same model group limits the risk of compatibility issues that may occur with replacements of different geometry or material hardness. Proper fitment is crucial for maintaining stable vacuum throughout the system.

Benefits of using an original vacuum pipe

Using an original Audi A5 S5 8T Brake Servo Vacuum Pipe Hose LIne Return Valve brings a number of practical benefits:

• Consistency with the factory design – maintaining the original operating characteristics of the brake servo.
• Reduced risk of leaks – matched connectors and proper pipe rigidity.
• Predictable brake system behavior – stable pedal response in various driving conditions.
• Easier diagnostics – component compliant with Audi service documentation.

This solution is especially recommended for repairs where the priority is to maintain safety and repeatability of the brake system operation in accordance with the manufacturer's assumptions.

Related components and service knowledge

During work on the vacuum system and brake servo, it is also worth paying attention to the condition of the vacuum pump itself and other pipes in the engine bay. If you are planning a comprehensive repair or upgrade of the braking zone in your Audi and need other elements from the same group, such as vacuum pipes, pumps, or control valves, check the available parts in the Audi Vacuum Pumps category.

For larger service work within the engine and accessories, knowledge regarding other key vehicle systems may also be helpful. To better understand the dependencies between engine supply and its accessories, it is worth referring to the guide material Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration, which facilitates the planning of comprehensive repairs and diagnostics.