Mercedes W168 Fuel Filler Cap Tank Cap Diesel Covering Black A1684700705

The Mercedes W168 Fuel Filler Cap is an original part from the Fuel Filler Flaps and Caps group, designed for diesel fuel systems. It ensures a tight seal for the filler neck, stabilizes the fuel system's operating conditions, and helps reduce fuel evaporation and the ingress of contaminants into the tank.

Specifications and technical data

• SKU: A1684700705
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1684700705
• Substitutable numbers: A1684700705, A 168 470 07 05, BG
• Location on the vehicle: Front, Left
• Fuel type: Diesel
• Color: Black
• Category: Fuel Tank Caps

Intended Use and Technical Function

The presented cap is dedicated to Mercedes vehicles from the W168 family, where the fuel filler is located in the front left part of the body. The design, adapted for diesel-powered systems, ensures proper sealing and resistance to typical operational loads in diesel engines.

The component is responsible for:

• maintaining the fuel filler's seal during daily operation,
• limiting the access of moisture and dirt to the filler neck,
• stabilizing pressure within the filler neck, depending on the fuel system's design.

Construction, Color, and Fitment

The cap is made in black, allowing for an aesthetic match with most body configurations and fuel filler recesses. The neutral color scheme facilitates integration with factory body elements and plastic covers, maintaining a cohesive look for the refueling area.

Thanks to its original manufacturing from the Mercedes range, correct dimensional tolerances are maintained, which translates to proper fitment with the filler socket and predictable behavior during repeated opening and closing.

Vehicle Placement and User Ergonomics

The cap is designed for installation in the front left part of the vehicle, in accordance with the factory structural layout of the W168 body. This placement facilitates access during refueling and allows for comfortable operation of the cap even in tight spaces at the pump.

This solution supports:

• intuitive location of the fuel filler by the driver,
• easy unscrewing and screwing of the cap without excessive strain on the threads,
• maintaining order and cleanliness in the refueling area.

Operational Characteristics and Benefits of Use

As a used part, the cap retains its manufacturer-intended functionality, offering an economical alternative to new components. This allows for reduced service costs while maintaining compliance with the vehicle's factory specifications.

Key advantages include:

• compatibility with diesel fuel systems,
• factory fitment to the filler neck geometry in W168 models,
• consistent black color that enhances the aesthetics of the refueling area,
• the ability to restore full fuel filler functionality without interfering with other components.

Integration with the Fuel System and Service Knowledge

Replacing the fuel filler cap is a simple yet important service task in the context of the entire fuel system's operation. A correctly selected part helps reduce the risk of contaminants entering the tank and supports stable fuel system operating conditions in the long term.

To better understand the relationships between the tank, fuel filler, and other fuel system components, it is worth consulting the educational material: Fuel System – Injectors, Pumps, and Fuel Tank: Maintenance and Repair, which provides practical tips on diagnostics and operation.

Expanding Service and Selecting Other Components

If you are planning a comprehensive repair or upgrade of the fuel filler area in your Mercedes and need other parts from the same group, such as additional caps, flaps, or filler covers, check the available parts in the Mercedes Fuel Filler Flaps and Caps category.

When planning your service budget, you can also consider wider use of used OEM-class parts – find out more about cost optimization and safe component selection in the article: Rising Repair Costs and the Boom in Used Parts – How to Save on Car Service?.