Mercedes R171 Roof Water Drain Pipe Hose Rear Left N/S Set A1716390394

Mercedes R171 Roof Water Drain Pipe Hose Rear Left N/S Set is a water drainage system component designed for the rear left section of the vehicle body. It is responsible for the controlled drainage of water from the folding roof area, which reduces the risk of moisture accumulation in the interior and structural components. This is a practical solution for users who want to restore the proper operation of the drainage system in their Mercedes in a controlled and predictable manner.

Specifications and technical data

• SKU: A1716390394
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1716390394
• Substitutable numbers: A1716390394, A 171 639 03 94
• Location on the vehicle: Rear, Left
• Category: Hoses, Lines & Pipes

Purpose and function of the drain hose

The presented hose belongs to the Lines, hoses and pipes group and is designed to operate in the rear left part of the vehicle. Its task is to drain water from the roof area to designated drainage points so that it does not accumulate in the sills, body cavities, or around the trunk upholstery.

A properly functioning roof water drain is important for:

• limiting corrosion of structural body components,
• reducing the risk of moisture in upholstery and soundproofing,
• maintaining stable operating conditions for the electrical system in the rear of the car,
• comfort of using the folding roof in daily operation.

Technical characteristics and installation

The hose is profiled for a specific location on the vehicle – rear, left side – which facilitates its proper routing in factory guides and brackets. This allows for maintaining the original geometry of the drainage system, and thus the correct direction of water flow.

The element comes from the Mercedes brand, which helps maintain compatibility with the factory body structure and existing mounting points. In practice, this translates into:

• easier fitment to existing passages and technological holes,
• stable seating of the hose without the need for modifications,
• consistency with other components of the roof drainage system.

Component condition and service application

The product is offered as a used original part, which allows for an economical repair of the water drainage system while maintaining compliance with the factory solution. This type of part is particularly useful in situations where the existing hose has cracked, leaked, become blocked, or was mechanically damaged during other service work.

Replacing the drain hose is recommended when symptoms appear such as:

• water appearing in the trunk or in the rear part of the cabin,
• traces of water stains near the left rear pillar or body cavities,
• improper water drainage after folding or washing the roof.

Benefits of using an original water drain hose

Using a dedicated drain hose in the rear left part of the body allows for restoring the predictable behavior of the water drainage system. A well-chosen element:

• reduces the risk of re-flooding sensitive body zones,
• supports maintaining stable operating conditions for the electrical system in the rear of the vehicle,
• helps maintain acoustic comfort and dry upholstery,
• facilitates further diagnostics of potential leaks within the roof area.

For users who care about the long-term operation of their convertible or roadster, it is important that a functional drainage system reduces the risk of costly repairs related to corrosion and interior moisture.

Related components and technical knowledge

If you are planning a comprehensive repair or upgrade of the roof water drainage zone in your Mercedes and need other elements from the same group, such as additional lines, hoses, or guide pipes, check the available parts in the Mercedes lines, hoses and pipes category.

To expand your knowledge about upgrades and component replacements in popular models, it is worth reading an article describing the evolution of construction and the selection of spare parts – you can find it here: Hot-hatch legend: the evolution of the VW Golf GTI from Mk1 to Mk8.