Mercedes Vito W639 Washer Bottle Tank Windscreen Reservoir A6398690320

Mercedes Vito W639 Washer Bottle Tank Windscreen Reservoir is an original component of the washer system, designed for professional windscreen maintenance in this model. Thanks to its factory-fit design for the Vito W639 body, it ensures stable mounting, proper hose routing, and correct operation of pumps and nozzles. It is a practical solution for workshops and users who want to maintain consistency with the vehicle's factory construction.

Specifications and technical data

• SKU: rhd-A6398690320-3
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6398690320
• Substitutable numbers: A6398690320, A 639 869 03 20
• Category: Washer Pumps, Reservoirs & Nozzles

Purpose and function in the washer system

The offered reservoir is a component from the Washer fluid reservoirs, pumps, and nozzles group, responsible for storing fluid and reliably supplying it to the washer pumps. A properly selected reservoir:

• ensures adequate fluid operating capacity,
• maintains system tightness during temperature fluctuations,
• allows for correct seating of pumps and level sensors (if present in the specific vehicle configuration),
• minimizes the risk of air entering the washer hoses.

Due to a design consistent with the factory specifications of the washer system in the Mercedes Vito W639, installation is predictable and repeatable, which is essential for both fleet vehicle servicing and individual commercial vehicles.

Benefits of using an original Mercedes reservoir

Choosing an original washer fluid reservoir for a Mercedes translates into a number of practical advantages in daily operation:

• Factory fit – preservation of original mounting points and geometry relative to the body and other engine bay components.
• Washer system compatibility – designated locations for pumps and connection ports, consistent with the Vito W639 installation.
• Stable system operation – reduced risk of leaks, seepage, and issues with fluid suction by the pumps.
• Easier diagnostics – maintaining the original design facilitates the identification of potential faults within the entire washer system.

Such a solution is particularly beneficial for commercial vehicles, where repair repeatability and predictable vehicle behavior during intensive use are paramount.

Condition, origin, and service application

The presented washer fluid reservoir is an original Mercedes brand component, sourced from dismantling. For workshops and users, this means the ability to use a part consistent with factory specifications while maintaining a favorable cost-to-quality ratio. A used component of this type is particularly effective in:

• post-accident repairs where the front part of the body has been damaged,
• cases of cracking or loss of tightness in the existing reservoir,
• servicing fleet vehicles where a quick return to service is a priority.

Thanks to the preservation of original geometry and mounts, the reservoir can be integrated into the existing system without the need for modifications to the washer installation.

Part selection by numbers and integration with other components

This reservoir model is assigned to a specific manufacturer reference, which facilitates its identification in service catalogs and when selecting parts by number. In practice, this allows you to:

• verify compatibility with a specific body version and model year of the Vito W639,
• check connections with other washer system elements, such as pumps or nozzles,
• reduce the risk of installing an incompatible component.

In case of doubts when selecting parts for fluid and fuel systems, it is worth consulting specialized technical materials. Extended information on diagnostics, selection by numbers, and operation can be found in the article Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration, which organizes the principles of working with media storage and pumping elements in a vehicle.

Expanding the washer system in a Mercedes

If you are planning a comprehensive repair or upgrade of the visibility and safety zone in your Mercedes and need other elements from the same group, such as additional reservoirs, pumps, or washer nozzles, check the available parts in the Mercedes washer fluid reservoirs, pumps, and nozzles category.

When choosing original components from dismantling, it is also worth considering the impact of such decisions on the future resale value of the vehicle. This issue is discussed in more detail in the guide Original used parts vs. resale value – how not to lose money?, which helps to plan repairs in an economical and technically justified manner.