Fuel Feed Line Mercedes W164 OM642 Return Line Pipe Hose A6420705532

Fuel Feed Line Mercedes W164 OM642 Return Line Pipe Hose is an original diesel engine fuel system component designed for the precise transport of diesel fuel in the OM642 unit. Thanks to its factory geometry and perfect fit for the specific W164 body configuration, these lines ensure stable injection system performance and compliance with factory safety standards. This is a solution for users who expect consistency with the original design and want to maintain the fuel system in accordance with the manufacturer's specifications.

Specifications and technical data

• SKU: A6420705532-2
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6420705532
• Substitutable numbers: A6420705532, A 642 070 55 32
• Fuel type: Diesel
• Category: Hoses, Lines & Pipes

Purpose and role in the fuel system

The fuel lines in the W164 model with the OM642 engine are responsible for the controlled flow of diesel fuel between key components of the fuel supply system. The properly selected diameter, shape, and routing of the lines limit pressure drops, minimize the risk of air ingress, and support stable injector operation. In diesel units, the proper condition of the fuel lines has a direct impact on engine refinement, ease of starting, and exhaust emission levels.

Compatibility with the diesel engine

The fuel supply system in a diesel engine operates under significant pressure loads, which is why fuel lines must be resistant to long-term contact with diesel fuel and variable thermal conditions in the engine bay. Using dedicated lines for the OM642 allows for maintaining:

• stable fuel flow parameters across the full load range,
• proper routing of the lines relative to engine accessories,
• reduction of vibrations and mechanical stresses that could lead to micro-cracks or leaks.

As a result, the fuel system remains consistent with the factory design, and the risk of fuel leaks or cold-start issues is significantly reduced.

Characteristics of the used component

The offered set of lines comes from disassembly and is classified as a used component, which represents a reasonable compromise between cost and maintaining the original manufacturer's specification. In practice, this means the ability to restore proper flow and fuel routing in the system without the need to use replacements with uncertain geometry. For many users of vehicles with the OM642 engine, this is an effective way to perform a technically correct repair while maintaining control over the service budget.

Benefits of using original fuel lines

Using lines dedicated to the W164 with the OM642 unit allows for maintaining the factory performance of the fuel supply system, which translates into:

• more predictable engine behavior in terms of power and torque,
• reduced risk of leaks and fuel seepage at critical points of the installation,
• easier diagnostics of potential injection system faults, thanks to the preservation of the original line routing.

For workshops and individual users, this means seamless integration with the existing system and no need to modify mounts or brackets in the engine bay.

Product group and additional system components

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 flexible line sections, rigid fuel pipes, or connecting hoses, check the available parts in the Mercedes lines, hoses, and pipes category.

To better plan service work on your car and understand the dependencies between individual sub-assemblies, it is also worth familiarizing yourself with practical tips regarding other systems, such as air conditioning – the article Air conditioning compressor – symptoms of failure, causes, and safe replacement may be helpful, as it facilitates the assessment of the compressor's condition and the approach to replacing used components.