Audi A4 B8 A5 8T Q5 8R A8 D3 Fuel Tank Filler Screw Cap Cover Diesel 8K0201550B

Visual condition of the part

The product shows signs of use visible in the photos.

Audi A4 B8 A5 8T Q5 8R A8 D3 Fuel Tank Filler Screw Cap Cover Diesel is an original component from the Fuel tanks and filler pipes group, designed for diesel fuel systems. It ensures a tight seal of the filler neck, stabilizes the operating conditions of the fuel system, and limits the ingress of contaminants into the tank. It is a practical solution for users who want to keep their fuel system in a predictable, safe operating condition.

Specifications and technical data

• SKU: 8K0201550B-2
• Mark: Audi
• Condition: Used
• OEM Part Number: 8K0201550B
• Substitutable numbers: 8K0201550B, 8K0 201 550 B
• Fuel type: Diesel
• Category: Fuel Tanks & Filler Necks

Purpose and function in the fuel system

The presented cap is a component designed for Audi vehicles with diesel engines. Its task is to maintain proper tightness of the filler neck, which limits fuel evaporation and minimizes the risk of moisture and fine contaminants entering the tank. A properly selected cap supports the stable operation of the fuel system and facilitates daily vehicle maintenance during refueling.

Thanks to a design consistent with factory solutions, the cap works with the geometry of the fuel filler in a given model, ensuring proper guidance and pressure after closing. This is particularly important in vehicles used intensively, where repeatability of operation and predictable component behavior have a direct impact on user comfort.

Technical characteristics and compatibility with the Diesel system

The cap has been designed with the specifics of diesel fuel systems in mind, where maintaining appropriate conditions in the fuel tank is important. The materials and sealing geometry are adapted for contact with diesel fuel, which promotes dimensional stability and resistance to typical operational loads. Using the correct cap reduces the risk of leaks that could lead to unpleasant odors, dirt ingress, or fuel tank venting problems.

As a component from the original Audi parts line, the cap is ready for use with the factory fuel system without the need for modifications. This is a beneficial solution for users who want to maintain the structural integrity of the vehicle and avoid problems resulting from the use of random replacements with uncertain parameters.

Condition, application, and benefits of installation

The offered cap is a used component, which in practice means the possibility of an economical replacement while maintaining compliance with factory solutions. For many users, this is a reasonable compromise between cost and functionality, especially for vehicles used daily, where restoring full fuel system functionality is a priority.

Replacing the fuel filler cap is recommended, among other situations, when:

• problems with closing occur or there is noticeable play on the thread,
• traces of dirt or moisture are visible around the filler neck after refueling,
• the existing component shows clear signs of mechanical wear.

Using an original cap allows you to restore proper filler operation, improve refueling comfort, and limit the risk of contaminants entering the tank.

Technical support and selection by part numbers

The component has a dedicated OEM part number and associated interchangeable numbers, which facilitates precise identification and selection for a specific model version. In practice, this means the possibility of verifying compatibility by catalog numbers, as well as by vehicle data, such as body generation or engine type. This is particularly important in the case of Audi models, where different fuel system variants exist depending on the year and configuration.

If you want to better understand the role of the filler cap in the entire fuel system, as well as the principles of diagnostics and component selection by catalog numbers, the guide article Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration, which discusses, among other things, the importance of tank tightness and proper component operation, will be helpful.

Expanding Audi fuel system maintenance

If you are planning a comprehensive repair or upgrade of the fuel system area in your Audi and need other components from the same group, such as filler pipes, mounting elements, or connection components, check the available parts in the Audi fuel tanks and filler pipes category.

For users who are also servicing other powertrain components in parallel, information regarding the selection of clutch and drivetrain elements may be useful – you can find them in the guide Clutch and dual-mass flywheel – diagnostics and selection of parts for the drivetrain, which will facilitate the planning of broader service work in one maintenance cycle.