Audi A4 B8 8K A5 8T Water Coolant Expansion Reservoir Tank 8K0121403Q

The Audi A4 B8 8K A5 8T Coolant Expansion Tank is an original cooling system component from the Expansion Tanks category, designed for precisely selected Audi models. Thanks to its factory design, it ensures proper operation of the cooling system, stable pressure, and safe overflow of excess fluid. This is a practical solution for users who want to maintain compliance with the manufacturer's factory standards.

Specifications and technical data

• SKU: 8K0121403Q
• Mark: Audi
• Condition: Used
• OEM Part Number: 8K0121403Q
• Substitutable numbers: 8K0121403Q, 8K0 121 403 Q
• Category: Expansion & Overflow Tanks

Intended Use and Model Fitment for Audi

The presented expansion tank has been specifically designed with the engine bay construction of the Audi A4 B8 generation and Audi A5 8T in mind. This means maintaining the correct position of the connectors, mounting points, and housing shape, which facilitates installation and reduces the risk of leaks. Its original Audi OE origin translates to consistency with the factory cooling system and compatibility with the equipment used in these models.

Technical Characteristics of the Expansion Tank

The tank belongs to the group of components responsible for compensating for coolant volume and maintaining stable pressure in the system. The design includes:

• a housing adapted for operation at elevated coolant temperatures,
• a space for a pressure cap matched to the Audi cooling system parameters,
• connections enabling proper flow and bleeding of the system.

By adhering to the factory design assumptions, the tank works with the sensors and hoses used in the specific vehicle generation, contributing to trouble-free operation.

Condition of the Part and Benefits of Using a Used Part

The offered expansion tank is a used part, allowing for economical repair of the cooling system while maintaining the original manufacturer's specifications. Choosing an original component from the aftermarket is a solution that often provides a better fit than many aftermarket replacements, while also reducing service costs. This type of part is suitable for both standard replacement of a worn-out tank and for a comprehensive cooling system overhaul after a failure.

Why Choose Original Audi Expansion Tanks

Factory Audi expansion tanks are designed for long-term cooperation with other cooling system components. Using an original solution:

• reduces the risk of problems with hose and bracket fitment,
• ensures compliance with the system's operating pressure parameters,
• supports stable engine operating temperatures, which is important for its durability.

For users who want to keep their car in a configuration close to the factory original, such a tank is a sensible choice in terms of technical and operational aspects.

Other Audi Expansion Tanks and Knowledge about Used Parts

If you are also looking for other Audi expansion tanks suitable for various models of this brand, check out the offer in the Audi expansion tanks category, where you will find a wide selection of cooling system components. To expand your knowledge about selecting original used parts, identification procedures by numbers, and practical aspects of operation, it is also worth reading the guide article on original used parts and their impact on the durability of premium cars.