Mercedes W177 Radiator Hose Connector Lock Expansion Tank Cap Plug A0079979089

Mercedes W177 Radiator Hose Connector Lock Expansion Tank Cap Plug is an original mounting component designed for the cooling system in Mercedes vehicles. It ensures a stable connection between the radiator hose and the expansion tank, which is essential for maintaining a leak-proof system and proper coolant circulation. This used OEM component is a practical solution for workshops and users looking for parts that are structurally matched to the factory system.

Specifications and technical data

• SKU: A0079979089
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0079979089
• Substitutable numbers: A0079979089, A 007 997 90 89, A 000 997 80 11, A0009978011
• Category: Other Engine Cooling Components

Purpose and technical function

The Mercedes W177 Radiator Hose Connector Lock Expansion Tank Cap Plug is responsible for mechanically securing the connection between the hose and the cooling system expansion tank. This component:

• maintains the hose in the correct position relative to the tank nozzle,
• reduces the risk of connection leaks during engine operation,
• supports system stability during changes in coolant temperature and pressure,
• facilitates service-related disconnecting and reconnecting of the hose without interfering with the tank structure.

Thanks to its fitment to the geometry of the factory connector, the lock works with original hoses and the tank, which helps maintain the operating parameters of the cooling system.

Benefits of using an original lock

Using an original lock in a Mercedes W177 is important for both durability and operational safety. In practice, this means:

• secure hose fastening without the need for additional clamps or modifications,
• preservation of the factory hose routing concept in the engine bay,
• reduced risk of coolant leaks at the connection point,
• easier diagnostics – the mechanic immediately sees that a component compliant with the factory solution has been used.

The used OEM component is also a favorable compromise between cost and quality, especially in the case of maintenance repairs or restoring functionality after local damage to the connector.

Service application and installation

The Mercedes W177 Radiator Hose Connector Lock Expansion Tank Cap Plug is designed for installation in place of the factory component, without the need for system modifications. In the context of service work, it is particularly useful in situations where:

• the original lock was mechanically damaged during hose removal,
• the connection between the hose and the tank has become unstable or has noticeable play,
• it is necessary to restore proper fastening after previous non-factory modifications.

Choosing an original lock allows for maintaining consistency with other cooling system components, which is important for the long-term operation of the vehicle.

Compatibility and part identification

The component has been designed for the Mercedes W177 platform, which ensures dimensional and structural compatibility with the factory cooling system. When selecting the lock, it is worth paying attention to:

• compatibility with the specific body and engine version within the W177 series,
• the type of radiator hose and expansion tank used,
• the presence of the appropriate locking socket in the existing system.

This helps avoid installation problems and ensures the proper operation of the hose-to-tank connection.

System expansion and related components

If you are planning a comprehensive repair or upgrade of the cooling system area in your Mercedes and need other parts from the same group, such as additional mounts, brackets, or small fasteners, check out the available parts in the Other Mercedes category.

For more extensive service projects or modifications, it is also worth expanding your knowledge about the structural differences between sports and standard vehicle versions – our blog article will help with this: Audi RS vs other models – what is hidden under the hood and chassis?, which discusses, among other things, the impact of changes in the cooling system, brakes, and chassis on the car's performance characteristics.

Summary

Mercedes W177 Radiator Hose Connector Lock Expansion Tank Cap Plug is a practical, original mounting component that allows you to restore proper hose fastening in the cooling system. Thanks to its fitment to the factory solution, it ensures a stable connection, supports system tightness, and facilitates service work, making it a functional choice for repairs and inspections of Mercedes vehicles.