Adblue Filler Cap Mercedes W166 W205 W213 C253 Tank Cover A0004700300

Mercedes W166 W205 W213 C253 AdBlue Filler Cap is an original part from the Oil Drain and Filler Caps and Dipsticks group, designed for the AdBlue dosing system in selected Mercedes models. It ensures a tight seal of the filler neck, reducing the risk of fluid evaporation, contamination, and issues with the exhaust emission reduction system.

Specifications and technical data

• SKU: A0004700300
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0004700300
• Substitutable numbers: A0004700300, A 000 470 03 00
• Category: Oil Drain Plugs, Filler Caps & Dipsticks

Purpose and Function of the AdBlue Filler Cap

The AdBlue filler cap in Mercedes vehicles is responsible for securely closing the fluid filler neck that supplies the Selective Catalytic Reduction (SCR) system. A correctly chosen part prevents moisture, dirt, and foreign objects from entering the tank, which helps maintain stable operating parameters of the exhaust purification system and reduces the risk of damage to dosing components.

Using the correct cap is particularly important in modern diesel engines where the AdBlue system interacts with engine electronics and fluid quality sensors. Leaks or improper fit can result in error messages, power loss, or the vehicle entering limp-home mode.

Why Choose an Original Mercedes Part

An original AdBlue filler cap for Mercedes is designed to match the specific filler neck geometry and the pressure-sealing requirements of the particular system. This ensures:

• a repeatable, tight seal of the filler neck,
• reduced risk of fluid crystallization around the cap,
• minimized possibility of damage to the filler neck thread or seat,
• compatibility with Mercedes' original design solutions.

Choosing an original component is especially beneficial for vehicles equipped with advanced onboard diagnostics, where even minor deviations from factory parameters can trigger system errors.

Performance Characteristics and Installation

This part from the Oil Drain and Filler Caps and Dipsticks group is structurally designed to operate in an environment with chemically active AdBlue fluid. The material and shape of the seal are adapted for frequent opening and closing cycles, allowing for multiple uses without significant loss of functionality.

The cap is installed intuitively – by screwing or snapping it into the filler neck socket, according to the factory solution used in the specific model. A correctly installed part should offer a noticeable final resistance, indicating a full closure and proper sealing.

Product Condition and Practical Application

The presented cap is a used part, allowing for an economical replacement of a damaged or lost component while maintaining compliance with Mercedes' factory specifications. This solution is particularly advantageous for maintenance repairs where functionality and compatibility with the existing system are the priority.

In practice, replacing the AdBlue filler cap is often the first step when dealing with filler neck leaks, spills around the cap, or visible mechanical damage (cracks, worn threads, missing sealing elements). Using the correct component helps restore proper SCR system operation without interfering with more expensive components.

Related Parts and Further Diagnostics

If you are planning a comprehensive repair or upgrade of the lubrication and fluid replenishment system in your Mercedes and need other parts from the same group, such as drain plugs, oil filler caps, or oil dipsticks, check the available parts in the category Mercedes Oil Drain and Filler Caps and Dipsticks.

For vehicles with advanced exhaust purification systems, it is also worth paying attention to the overall condition of the engine and its accessories. You can read more about the impact of engine operating temperature and the role of the cooling system in protecting components in the article: Engine Cooling System – Overheating, Repair, and Used Radiators.

If you are considering whether new or used parts would be a better choice for your situation, a comparison of costs and durability described in the material may be helpful: Car Parts – New or Used? Comparing Costs, Quality, and Durability.