Mercedes W639 Fuel Tank Diesel Bare Fuel Tank Unit 75L A6394711401

Visual condition of the part

The product shows signs of use visible in the photos.

Mercedes W639 Fuel Tank Diesel Bare Fuel Tank Unit 75L is a factory-made fuel system component designed for Mercedes vehicles with a diesel engine. The tank belongs to the Fuel tanks and filler pipes category and is offered as a "bare" unit – without a fuel pump, which allows you to use the vehicle's existing equipment or select accessories according to your specific needs.

Specifications and technical data

• SKU: A6394711401-3
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6394711401
• Substitutable numbers: A6394711401, A 639 471 14 01, A6394702094, A 639 470 20 94
• Fuel type: Diesel
• Category: Fuel Tanks & Filler Necks

Purpose and role in the fuel system

The presented fuel tank is a structural component of the fuel system in Mercedes W639 series commercial/van vehicles. Its task is to safely store diesel fuel and work in conjunction with factory equipment – the pump, fuel level sensors, and supply lines. The bare version without a pump allows for the transfer of original components from the previous tank, which reduces repair costs and makes it easier to maintain compliance with the vehicle's factory configuration.

The tank is adapted for use in systems where the working medium is Diesel fuel. This ensures material compatibility with diesel oil and typical operational additives used in modern diesel engines.

"Bare" construction and installation benefits

The variant without a fuel pump is particularly beneficial in situations where the tank housing itself has been damaged (e.g., corrosion, mechanical damage), while the accessories remain functional. This allows you to:

• retain the original pump and fuel level sensors,
• reduce the cost of the entire service operation,
• select accessories individually – e.g., based on the VIN or vehicle equipment specifications.

A working capacity of 75 liters ensures an appropriate vehicle range given the typical fuel consumption of diesel units used in the Mercedes W639, which is important for both fleet applications and private use.

Condition, verification, and selection based on technical data

The item is offered as a used part, which allows for optimized repair costs while maintaining the manufacturer's original specifications. Before installation, a standard check of tightness, the condition of connection ports, and mounting points to the chassis is recommended. It is worth basing the selection of the tank on the vehicle's technical data and catalog numbers – especially in the case of different engine variants and body lengths in the W639 series.

To better understand the relationships between the tank, pump, and injectors, and to properly plan diagnostics, regeneration, or replacement of fuel system components, it is worth consulting our guide: Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration. The article discusses, among other things, selecting parts by OEM and VIN numbers as well as typical service procedures.

Integration with the Mercedes Fuel tanks and filler pipes category

If you are planning a comprehensive repair or upgrade of the fuel system area in your Mercedes and need other elements from the same group, such as filler hoses, breather ports, or additional mounting elements, check the available parts in the Mercedes Fuel tanks and filler pipes category.

Summary of application in the Mercedes W639

Mercedes W639 Fuel Tank Diesel Bare Fuel Tank Unit 75L is a solution intended for users who want to restore full functionality to the fuel system while keeping costs under control. The original construction, adaptation for Diesel fuel, and the ability to use existing accessories make it a practical choice for post-accident repairs, mechanical damage, or tank corrosion. A properly selected and installed tank supports stable diesel engine operation and safe fuel storage in daily use.