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

Mercedes W639 Fuel Tank Diesel Complete Fuel Tank Unit 75L is a complete solution for the fuel supply system in diesel engines, designed for the W639 series models. This component belongs to the Fuel tanks and filler pipes category, ensuring stable diesel storage and efficient fuel delivery to the injection system. It is a practical choice for repairs where structural compatibility with the factory Mercedes solution is essential.

Specifications and technical data

• SKU: A6394711401-2
• 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 function in the fuel system

The offered fuel tank integrated with a pump is a component dedicated to Mercedes W639 series vehicles powered by diesel fuel. It is responsible for safe Diesel fuel storage, pre-filtration, and stable delivery to subsequent system components, such as lines, the fuel filter, and injectors. Using the correct tank with the appropriate pump reduces the risk of air ingress, pressure drops, and cold start issues.

Construction and key technical features

The set includes a fuel tank with a built-in pump, which simplifies the service process – you replace the entire unit instead of selecting individual components separately. The design is adapted to the geometry of the W639 chassis, ensuring that the correct mounting points, line routing, and the position of supply and return ports are maintained. The tank is adapted for operation with a Diesel fuel system, which is significant in terms of both material resistance and pump operating parameters.

The original origin from the Mercedes group means maintaining factory standards regarding tightness, vibration resistance, and compatibility with vehicle equipment (fuel level sensors, mounts, clamps, brackets). As a result, the risk of installation problems is limited, and the fuel system can operate under conditions close to factory specifications.

Condition, selection, and service application

The item is in used condition, making it a reasonable cost alternative for maintenance repairs or restoring vehicle functionality after mechanical damage. In the case of fuel systems, matching by manufacturer markings is particularly important – therefore, before purchasing, it is worth verifying compatibility by OEM number or interchangeable numbers, as well as by vehicle data (model, year, engine version).

A tank and pump unit configured in this way will prove useful for, among others:

• repairs after corrosion or mechanical damage to the tank,
• problems with fuel suction and pressure drops in the system,
• comprehensive regeneration of the fuel supply system in a diesel engine,
• restoring vehicle functionality after a collision or bodywork repairs in the chassis area.

Benefits of using an original tank with a pump

Using an original Mercedes solution allows you to maintain the factory characteristics of the fuel system operation, which translates into stable supply pressure, correct starting, and smooth engine operation. A tank designed specifically for diesel units reduces the risk of leaks, improper venting, and fuel level reading errors. Compared to universal replacements, the fit of the shape and mounts facilitates installation and shortens vehicle downtime in the workshop.

For workshops and fleet users, this is also a way to maintain component consistency in the vehicle – the original tank geometry facilitates subsequent services, and access to Mercedes technical documentation allows for precise planning of further maintenance activities.

Selection by numbers and technical support

For components such as a fuel tank with a pump, matching by manufacturer numbers and fuel type is crucial. In this case, we are dealing with a Diesel system, so before installation, ensure that the vehicle is equipped with the appropriate power unit and equipment. In case of doubt, it is worth consulting the selection with a mechanic or using a parts catalog by OEM number and interchangeable numbers to avoid compatibility issues.

If you are planning a comprehensive repair or upgrade of the fuel supply area in your Mercedes and need other components from the same group, such as additional tanks, lines, or filler pipes, check the available parts in the Mercedes fuel tanks and filler pipes category.

More about fuel system operation

To maximize the potential of this component, it is worth familiarizing yourself with the principles of diagnostics and operation of the entire supply system. Detailed information on the operation of injectors, pumps, and fuel tanks, as well as practical tips on selecting parts by OEM numbers and regeneration, can be found in the article Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration.