Ford Focus Mk2 Coolant Expansion Tank Radiator Overflow Bottle 3M5H-8K218-AH

Ford Focus Mk2 Coolant Expansion Tank Radiator Overflow Bottle is an original cooling system component designed for stable engine operation across a wide temperature range. This Ford Focus Mk2 Coolant Expansion Tank Radiator Overflow Bottle ensures proper compensation of fluid volume, facilitates system bleeding, and allows for visual inspection of the working fluid level.

Specifications and technical data

• SKU: 3M5H-8K218-AH
• Mark: Ford
• Condition: Used
• OEM Part Number: 3M5H-8K218-AH
• Substitutable numbers: 3M5H-8K218-AH, 3M5H8K218AH, 1425193, 3M5H-8K218-AJ, 3M5H8K218AJ
• Category: Expansion & Overflow Tanks

Purpose and function in the cooling system

The offered expansion tank is a cooling system component dedicated to the Ford Focus Mk2, designed as an original manufacturer part. Its task is to take in excess coolant as the temperature rises, stabilize system pressure, and allow for the safe return of fluid once cooled.

Thanks to a properly shaped working chamber and connection ports, the tank works with cooling system hoses, reducing the risk of airlocks and localized overheating. The transparent body material facilitates ongoing fluid level monitoring without the need to disassemble the component.

Original origin and installation compatibility

This is a part from the Expansion tanks group prepared by the Ford brand, maintaining factory manufacturing standards. This ensures the correct geometry of mounts, port diameters, and housing shape, which translates into secure seating in the engine bay and proper hose routing.

The item has an assigned OEM part number and associated interchangeable numbers, which facilitates verification of compatibility with a specific vehicle equipment version. Before purchasing, it is worth comparing the used reference with service documentation or the currently installed tank to ensure full installation compatibility.

Performance characteristics and benefits of use

The original Ford Focus Mk2 Coolant Expansion Tank Radiator Overflow Bottle provides:

• stable cooling system operation under variable engine loads,
• the ability to quickly check the coolant level,
• proper routing of lines and hoses thanks to factory mounts,
• consistency with other vehicle cooling system components.

The used condition allows for an economical replacement of a damaged or leaking tank while maintaining the original design. This is a practical solution in situations where the existing component shows signs of cracks, discoloration, or problems with maintaining system pressure.

Practical installation tips

When replacing the expansion tank, it is recommended to:

• check the condition of supply hoses and clamps,
• check the quality of the coolant and replace it with new fluid if necessary,
• thoroughly bleed the system after installation, in accordance with the Ford service procedure.

Selecting an original tank from the same design group minimizes the risk of leaks and fitment issues, which shortens service time and facilitates subsequent vehicle operation.

If you are planning a comprehensive repair or upgrade of the cooling system area in your Ford and need other components from the same group, such as additional tanks, auxiliary elements, or compatible fluid reservoirs, check the available parts in the Ford Expansion tanks category.

Additional inspiration and vehicle development

During service work on the cooling system, it is also worth considering improving the ergonomics and aesthetics of the car's interior. You can read about the possibilities of using used interior components, such as seats or steering wheels, in the article Car interior tuning with Global Parts, which shows how to reasonably combine functionality with cost control.