Ford Focus St-3 Mk3 Fuel Filter Housing Cover Box 2.0 Petrol R9DA 7M51-9E857-FC

Ford Focus St-3 Mk3 Fuel Filter Housing Cover Box 2.0 Petrol R9DA is an original fuel system component designed for petrol engines in the sporty ST-3 version. The robust construction of the housing ensures stable seating of the filter element and secure fuel routing, which translates into reliable engine performance and predictable operating parameters. This solution is particularly valued during dynamic driving, where the fuel system operates under increased load.

Specifications and technical data

• SKU: 7M519E857FC
• Mark: Ford
• Condition: Used
• OEM Part Number: 7M519E857FC
• Substitutable numbers: 7M519E857FC, 7M51-9E857-FC
• Fuel type: Petrol
• Part type: Fuel Filter
• Category: Fuel Filters

Purpose and role in the fuel system

The fuel filter housing in the ST-3 Mk3 version is responsible for tight fuel routing and correctly maintaining the filter element in its intended operating position. In the 2.0 R9DA petrol engine, this has a direct impact on:

• stable pressure in the fuel supply system at high RPMs,
• protection of injectors against contaminants,
• maintaining repeatable air-fuel mixture parameters,
• reducing the risk of leaks at fuel line connections. Thanks to its factory fitment to the Focus ST-3 design, the housing works with other fuel system components without the need for modifications or adaptations.

Benefits of using an original fuel filter housing

Using an original housing in the Fuel filters category allows you to maintain the parameters specified by the vehicle manufacturer. In practice, this means:

• secure fitment with brackets and fuel lines in the engine bay,
• proper cooperation with the filter element dedicated to the specific engine,
• preservation of factory fuel flow geometry,
• reduced risk of micro-leaks and air entering the system. For petrol engines, stability of supply during sudden load changes is particularly important, which is why choosing the right fuel filter housing is significant not only for maintenance but also for performance.

Product characteristics and condition

The presented fuel filter housing comes from the Ford range and is a used item, which in practice means it was previously used in a vehicle but has retained functionality allowing for further use. This type of component is particularly attractive to users who:

• are looking for parts structurally matched to the ST-3 Mk3 version,
• want to reduce service costs while maintaining original specifications,
• prefer components sourced from the dismantling of a factory fuel system. The housing is designed for petrol engines, ensuring compliance with material and structural requirements for this type of fuel.

Selection, installation, and fuel system compatibility

To correctly select the fuel filter housing for a specific Focus ST-3, it is worth verifying compatibility based on manufacturer markings and engine parameters. A properly selected element:

• enables installation in existing mounting points,
• ensures compatibility with fuel lines and quick-connectors,
• allows for trouble-free replacement of the filter element in the future. For users who want to better understand the operation of the entire fuel system, diagnostics, and component selection by manufacturer markings, the following guide will be helpful: Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration. The article discusses, among other things, the principles of selecting parts by numbers and the impact of the fuel system's condition on engine operation.

Expanding service within Ford fuel filtration

If you are planning a comprehensive repair or upgrade of the fuel supply area in your Ford and need other elements from the same group, such as filter elements, mounting brackets, or supply lines, check the available parts in the Ford Fuel filters category.