Mercedes R129 SL W140 W202 W220 Coolant Expansion Tank Cap A2105010315

Mercedes R129 SL W140 W202 W220 Coolant Expansion Tank Cap is an original cooling system component from the Expansion tanks category, designed for use in selected Mercedes models. This used component allows for a technical, economical, and safe replacement of a worn cap, while maintaining the factory operating parameters of the cooling system. It is a practical solution for users who expect a solid fit and compatibility with the vehicle's design.

Specifications and technical data

• SKU: A2105010315
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2105010315
• Substitutable numbers: A2105010315, A 210 501 03 15
• Part type: Coolant Expansion Tank
• Category: Expansion & Overflow Tanks

Purpose and technical function

The expansion tank cap in the cooling system is responsible for maintaining the correct operating pressure and the tightness of the fluid circuit. For Mercedes R129 SL, W140, W202, and W220 models, using the correct cap is important for:

• stable operation of the cooling system under various engine load conditions,
• reducing the risk of engine overheating,
• maintaining the correct fluid level in the expansion tank,
• maintaining compliance with the factory system design. Thanks to the preservation of the original geometry and mounting method, the cap works with the factory expansion tank, which facilitates installation and reduces the risk of leaks.

Benefits of using an original Mercedes cap

Using an original expansion tank cap in Mercedes cars brings a number of practical operational benefits. The element is designed for a specific cooling system construction, which translates into:

• a secure fit to the expansion tank without the need for modifications,
• maintenance of factory operating pressure parameters,
• consistency with other cooling system components,
• reduction of the risk of failures resulting from the use of random replacements. A used, original cap is a reasonable choice when servicing older generations of Mercedes vehicles, where both technical compliance and repair cost control are important.

Product condition and service application

The offered cap comes from the Mercedes range and is marked as a secondary market product (used condition). This type of part is suitable for situations where the existing cap shows signs of wear, such as leaks, problems with maintaining pressure, or visible mechanical damage. Replacing the cap is one of the simpler service tasks in the cooling system area, and a correctly selected element helps to restore proper engine operating conditions. For workshops and users servicing the vehicle themselves, using an original expansion tank cap is a convenient way to maintain consistency with the vehicle's factory specifications without having to reach for new, more expensive components.

Cooling system service expansion and related categories

If you are planning a comprehensive repair or upgrade of the cooling system area in your Mercedes and need other elements from the same group, such as an expansion tank, supply hoses, or additional mounting elements, check the available parts in the Mercedes expansion tanks category. For more extensive service work, including the drivetrain, educational materials on diagnostics and component selection may be helpful. In such a case, it is worth reading an article describing a practical approach to assessing wear and selecting parts for the drivetrain system: Clutch and dual-mass flywheel – diagnostics and selection of parts for the drivetrain system.

Summary

Mercedes R129 SL W140 W202 W220 Coolant Expansion Tank Cap is a practical choice for users and workshops servicing older Mercedes models who expect compliance with the factory cooling system design. A used, original element allows for a technically correct replacement of a worn cap, supporting stable engine operation and maintaining proper coolant parameters in daily use.