Audi A4 B9 Master Cylinder Brake Fluid Reservoir Run On Hose Tube Line 8W0721453

Audi A4 B9 Master Cylinder Brake Fluid Reservoir Run On Hose Tube Line is an original brake system component designed for the precise delivery of fluid from the reservoir to other system components. Being a factory-original part from Audi, it ensures proper geometric fitment and compatibility with the vehicle's brake system design. This is a practical solution for users who want to maintain consistency with factory specifications and ensure stable brake performance.

Specifications and technical data

• SKU: 8W0721453
• Mark: Audi
• Condition: Used
• OEM Part Number: 8W0721453
• Substitutable numbers: 8W0721453, 8W0 721 453
• Part type: Hose
• Category: Brake Hoses, Lines & Fittings

Purpose and function in the brake system

The described hose is responsible for the safe routing of brake fluid between the reservoir and other system components. A properly selected tube minimizes the risk of air ingress, leaks, and uncontrolled pressure drops, which translates into predictable brake pedal operation. In modern designs, such as the Audi A4 B9 generation, maintaining the original hose geometry is crucial for the stability of the entire system.

Construction and fitment for Audi A4 B9

The hose has been designed specifically for the body and engine bay architecture of the Audi A4 B9, taking into account the routing of the brake system and the placement of mounts. The appropriately selected length, shape, and internal diameter allow for:

• maintaining proper brake fluid flow,
• secure seating in sockets and connectors,
• reducing stress resulting from body movement and engine vibrations.

As a result, installation is straightforward, with no need to modify other components in the engine bay.

Benefits of using an original hose

Using an original brake fluid reservoir hose in an Audi A4 B9 allows you to maintain the parameters specified by the vehicle manufacturer. In practice, this means:

• stable operating pressure in the brake system under typical operating loads,
• reduced risk of micro-leaks at connections,
• compatibility with factory connectors and mounting brackets,
• easier diagnostics and future service, thanks to maintaining the original hose routing.

This is particularly important for vehicles equipped with advanced brake assist systems, where the quality and integrity of the hoses have a direct impact on the effectiveness of the electronics.

Characteristics of the used component

The offered hose comes from dismantling, which allows you to combine reasonable costs with the preservation of factory specifications. A used brake system component of this type is a popular choice in situations where:

• it is necessary to replace a damaged tube after a collision or mechanical interference,
• the existing hose has cracked, chafed, or become deformed,
• the priority is to maintain the original installation routing without using universal replacements.

Choosing such a solution is often economically advantageous while maintaining compliance with the vehicle manufacturer's design.

Expansion and service of the Audi brake system

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 additional flexible hoses, rigid lines, or service connectors, check out the available parts in the Audi brake hoses, lines, and connectors category.

When selecting reclaimed components for the brake system, it is worth following proven service practices. You can find more information on the safe use of original, used brake components and ways to optimize repair costs in the article: Brake calipers under the microscope: How to effectively reduce brake system repair costs by choosing proven reclaimed parts.