Ford Focus Mk3 Radiator Expansion Overflow Reservoir Tank Bottle 8V61-8K218-AE

The Ford Focus Mk3 Coolant Expansion Tank is an original cooling system component designed for stable engine operation under demanding conditions. This factory overflow tank ensures proper fluid volume compensation, facilitates level checks, and supports safe excess coolant drainage. As a part from the Expansion Tanks category, it is a key component for maintaining the engine's optimal temperature.

Specifications and technical data

• SKU: 8V61-8K218-AE
• Mark: Ford
• Condition: Used
• OEM Part Number: 8V61-8K218-AE
• Substitutable numbers: 8V61-8K218-AE, 8V618K218AE, 1717053
• Part type: Coolant Expansion Tank
• Category: Expansion & Overflow Tanks

Purpose and Function in the Cooling System

The original expansion tank for the Ford Focus Mk3 operates within the coolant circuit as a component that compensates for pressure and volume changes. It enables:

• safe storage of excess coolant during temperature increases,
• coolant return to the system when temperature drops,
• visual inspection of the coolant level,
• stabilization of the entire cooling system's operation.

Thanks to its carefully designed geometry and connection ports, the tank works seamlessly with the factory engine equipment, maintaining the parameters specified by the vehicle manufacturer.

Original Origin and Fitment

As a Ford branded part, the expansion tank has been specifically designed for the engine bay architecture of the third-generation Focus. This ensures:

• compatibility with factory mounting points,
• correct positioning of ports relative to coolant hoses,
• maintenance of the manufacturer-specified working capacity,
• consistency with original equipment and covers.

Such precise fitment minimizes the risk of leaks, hose stress, and air bleeding issues, which are crucial for both durability and operational safety.

Performance Characteristics and Installation Benefits

The used expansion tank for the Ford Focus Mk3 is a solution that allows for technically correct cooling system repairs while maintaining a favorable cost-to-quality ratio. Key advantages include:

• factory geometry and threads – facilitate installation and integration with original components,
• compatibility with manufacturer-specified sensors and hoses,
• direct replacement of a damaged tank without any modifications to the installation.

Choosing an original tank from the same design group minimizes the risk of fitment problems often encountered with universal parts or low-quality aftermarket alternatives.

Component Condition and Service Application

The offered tank comes from the used Ford parts segment, making it a practical choice for operational repairs, replacement after housing cracks, or damaged ports. It is particularly suitable for situations where maintaining the original cooling system specification while optimizing service costs is a priority.

Expanding the Ford Cooling System

If you are planning a comprehensive repair or upgrade of the engine bay in your Ford and require other parts from the same group, such as additional tanks, mounting elements, or related cooling system components, check the available parts in the Ford Expansion Tanks category.

For drivers who are simultaneously servicing their drivetrain and want to better understand the relationship between engine load, clutch operation, and engine operating temperature, the guide article Clutch and Dual-Mass Flywheel – Diagnostics and Part Selection for the Drivetrain may be helpful, offering practical service tips and application examples.