Breather Hose Mercedes W205 Diesel M626 Expansion Tank Radiator Line A2055012925

Breather Hose Mercedes W205 Diesel M626 Expansion Tank Radiator Line is an original cooling system component designed for diesel engines. It ensures stable air and coolant discharge between the expansion tank and the radiator, which translates into safe thermal operation of the power unit and reduces the risk of overheating. This is a practical service solution for users who want to restore proper circulation in the cooling system without unnecessary modifications.

Specifications and technical data

• SKU: A2055012925
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2055012925
• Substitutable numbers: A2055012925, A 205 501 29 25
• Fuel type: Diesel
• Category: Coolant Hoses

Function in the diesel engine cooling system

The breather hose in the cooling system plays a key role in pressure stabilization and removing air bubbles from the coolant circuit. In Diesel engines, proper venting is particularly important because diesel units generate high thermal loads. Using a dedicated hose for the specific W205 body generation allows for maintaining the correct coolant flow between the expansion tank and the radiator, which supports uniform cooling of all engine sections.

Compatibility and fit for Mercedes W205

The offered hose has been designed for the Mercedes W205 platform with a diesel engine, ensuring that its geometry, connection diameters, and routing are adapted to the factory layout in the engine bay. This means:

• secure seating on the expansion tank and radiator ports,
• compatibility with original brackets and guides,
• no need to modify other cooling system components.

Such a fit reduces the risk of leaks, facilitates installation, and allows for maintaining the factory hose routing in the engine bay, which is important for both service and subsequent diagnostics.

Performance characteristics of the used component

The hose comes from the secondary market, which represents a reasonable compromise between repair costs and maintaining the manufacturer's original specifications. A used cooling system component is a good solution in situations where:

• the existing hose has cracked, chafed, or deformed,
• a quick replacement is necessary without waiting for rarely available new parts,
• maintaining the original hose routing in the engine bay is a priority.

Using an original breather hose allows for maintaining the integrity of the cooling system with other components, which promotes stable engine operation across a wide temperature range.

Importance of proper cooling system venting

A functional breather hose has a direct impact on maintaining the correct coolant level in the expansion tank and on the efficient discharge of excess air from the circuit. In practice, this translates into:

• more uniform temperature distribution in the engine block and cylinder head,
• reduced risk of local overheating and cavitation in the coolant pump,
• stable operation of the thermostat and radiator fans.

For users operating their vehicle in urban and highway conditions, maintaining a functional breather hose is one of the simplest ways to increase the reliability of the cooling system without costly modifications.

Technical support and additional materials

If you want to better understand how high ambient temperatures affect the operation of the radiator, fans, and hoses in your car, check out our guide: Summer heat vs. cooling system: used radiators and fans as a guarantee of savings. You will find practical tips there regarding the operation and maintenance of components responsible for heat dissipation.

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other components from the same group, such as return lines, coolant supply hoses, or breather lines, check out the available parts in the category Mercedes cooling system hoses and lines.