Mercedes W447 Brake Servo Fluid Reservoir Expansion Tank Bottle A4474310402

Mercedes W447 Brake Servo Fluid Reservoir Expansion Tank Bottle is an original brake system component designed to function as a brake fluid reservoir and servo expansion tank in vehicles of this series. This used, factory-original Mercedes part ensures proper storage and stable fluid delivery to the system, which translates into predictable brake performance and safe vehicle handling.

Specifications and technical data

• SKU: rhd-A4474310402
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A4474310402
• Substitutable numbers: A4474310402, A 447 431 04 02
• Category: Reservoirs & Caps

Purpose and function in the brake system

The presented reservoir operates in the brake servo area, responsible for maintaining the correct fluid level and delivering it to the master cylinder and other system components. The design provided by the vehicle manufacturer allows for:

• stable hydraulic supply to the brake circuits,
• fluid level monitoring in the engine bay,
• reduced risk of air entering the system when installed correctly.

As a result, the brake system maintains proper operating parameters, and the response to the brake pedal remains consistent and predictable.

Design and fitment for Mercedes W447

The Mercedes W447 Brake Servo Fluid Reservoir Expansion Tank Bottle has been designed as an OEM component, which means a perfect fit for the factory servo, lines, and mounting points in the engine bay. The properly shaped housing and connection ports facilitate installation and minimize the risk of leaks when using the correct seals.

The original construction ensures compatibility with factory fluid level sensors (if present in the vehicle's specific configuration) and correct routing of brake lines in accordance with the manufacturer's specifications.

Condition, origin, and benefits of using a used part

The offered reservoir comes from the Brake fluid reservoirs and caps group and is a used item, which allows for combining reasonable repair costs with maintaining the original manufacturer's specifications. In practice, this means:

• preservation of factory geometry and mounting points,
• material compatibility with the Mercedes brake system,
• the possibility of an economical replacement for a damaged or leaking reservoir.

Choosing an original used part is particularly beneficial for premium class vehicles, where aftermarket replacements often differ in manufacturing details, affecting durability and ease of maintenance.

Safety, operation, and good service practices

When replacing the brake fluid reservoir, it is recommended to simultaneously check the condition of the lines, the servo, and the quality of the fluid itself. A properly selected and installed reservoir helps maintain system integrity and facilitates subsequent bleeding and periodic fluid changes. It is worth paying attention to:

• precise seating of the reservoir on the servo or dedicated mounts,
• checking the condition of seals and connection ports,
• maintaining the correct fluid level according to the markings on the housing.

For users who want to better understand the impact of individual components on brake service costs, the following guide material will be useful: Brake calipers under the microscope – how to reduce brake system repair costs by choosing proven recycled parts.

Comprehensive approach to the Mercedes brake system

If you are planning a comprehensive repair or upgrade of the braking zone in your Mercedes and need other elements from the same group, such as additional reservoirs, caps, or mounting hardware, check the available parts in the Mercedes brake fluid reservoirs and caps category.

If you are interested in the broader context of using original, used components in premium class cars, it is worth reading our market analysis: why used original parts for premium brands, such as Mercedes, are becoming an increasingly popular choice. This will allow you to consciously plan future repairs and vehicle upgrades.