Ford Focus Mk3 ST Coolant Expansion Tank Overflow Bottle 2.0 Petrol CV61-8K218-B

Ford Focus Mk3 ST Coolant Expansion Tank Overflow Bottle 2.0 Petrol is an original cooling system component designed for use in petrol engines. Engineered by the vehicle manufacturer, it ensures stable thermal conditions for the power unit and safe operation of the entire cooling system under demanding operating conditions.

Specifications and technical data

• SKU: CV61-8K218-B
• Mark: Ford
• Condition: Used
• OEM Part Number: CV61-8K218-B
• Substitutable numbers: CV61-8K218-B, CV618K218B
• Fuel type: Petrol
• Part type: Coolant Expansion Tank
• Category: Expansion & Overflow Tanks

Purpose and function in the cooling system

The presented expansion tank is a cooling system component responsible for compensating for coolant volume changes and maintaining a stable level of the working fluid. In the version designed for the Ford Focus Mk3 ST with a 2.0 petrol engine, it operates under conditions of increased thermal load, typical for units with sporty characteristics. Thanks to the factory geometry of the connectors and the shape of the housing, the tank works with the original engine bay equipment, which facilitates installation and maintains proper coolant circulation. The appropriately selected working capacity allows for effective discharge of excess fluid and pressure control within the system.

Benefits of using an original expansion tank

Using an original expansion tank in a Ford Focus Mk3 ST translates into a number of practical operational benefits:

• secure fitment to factory mounts and cooling system hoses,
• maintenance of the system's operating characteristics as designed by the manufacturer,
• reduction of the risk of leaks resulting from poor fitment,
• stable engine thermal conditions during dynamic driving. Combined with a properly selected coolant, the tank helps maintain a safe operating temperature for the power unit, which is important for both performance and the durability of the petrol engine.

Product characteristics and condition

The offered item comes from the Expansion tanks group and is intended for reinstallation in a vehicle. As a used part, it provides a cost-effective solution for users who want to restore full cooling system efficiency while maintaining a component consistent with Ford's factory specifications. Selecting the correct tank for a Ford Focus Mk3 ST with a 2.0 petrol engine helps avoid compatibility issues, such as incorrect connector positioning or differences in mounting methods. This is particularly important in high-performance vehicles, where the cooling system operates under greater load.

Professional installation and operation

When replacing the expansion tank, it is recommended to:

• check the condition of the cooling system hoses and clamps,
• verify for leaks after filling the system with fluid,
• bleed the system according to the service procedure for the specific model,
• use coolant with parameters recommended by the vehicle manufacturer. This approach minimizes the risk of engine overheating and allows for full utilization of the tank's design features in daily operation, both in city traffic and during more dynamic driving.

Related items and additional information

If you are planning a comprehensive repair or upgrade of the engine area in your Ford and need other items 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 users interested in a broader approach to servicing systems responsible for thermal comfort in the vehicle, the guide article Air conditioning and heating – part selection and maintenance for year-round comfort may be useful, where the principles of selecting used OEM components and maintenance schedules are discussed.