Mercedes W205 OM651 Coolant Radiator Expansion Tank Bleed Line A2055012225

Mercedes W205 OM651 Coolant Radiator Expansion Tank Bleed Line is an original cooling system component designed for precise air evacuation and pressure stabilization within the coolant circuit. Thanks to its factory-fit design for the OM651 engine in the W205 model, it ensures proper interaction between the expansion tank and the radiator, which translates into safe engine operation across a wide temperature range. This is a practical solution for users looking for a proven, used component with maintained functionality.

Specifications and technical data

• SKU: A2055012225
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2055012225
• Substitutable numbers: A2055012225, A 205 501 22 25
• Category: Coolant Hoses

The role of the bleed line in the cooling system

The presented bleed line is responsible for the controlled flow of medium between the expansion tank and the radiator, which allows for the effective removal of air bubbles from the circuit. A properly functioning hose reduces the risk of localized overheating, supports stable operating pressure, and facilitates the maintenance of the correct coolant level. For OM651 diesel units, this is of particular importance for maintaining uniform operating temperatures and protecting critical engine components.

Construction and fitment for Mercedes W205 OM651

The hose has been designed specifically for the engine bay architecture of the Mercedes W205 with the OM651 unit, which ensures factory-standard hose routing and no interference with other auxiliary components. The appropriately selected diameter and cross-sectional shape allow for stable flow and proper cooling system bleeding without the need for modifications or adapters. The materials used are adapted for operation at elevated temperatures and in contact with coolant, which promotes durability and consistent performance parameters.

Benefits of using an original hose

Using an original bleed line instead of a worn or leaking component allows you to:

• restore proper circulation and bleeding of the cooling system,
• minimize the risk of engine overheating and operating temperature fluctuations,
• maintain compliance with the manufacturer's factory specifications,
• avoid fitment issues typical of aftermarket parts with universal geometry.

For users who value the integrity of the entire cooling system and predictable vehicle behavior in both city and highway conditions, choosing an original hose is a reasonable compromise between cost and functionality.

Used condition and installation aspects

The item is offered in used condition, which allows for an economical repair while maintaining the original design. Before installation, a standard visual inspection for any signs of wear is recommended, followed by proper seating on the expansion tank and radiator connectors using appropriate clamps. Thanks to its factory shape, the hose allows for plug-and-play installation without the need to modify other cooling system components.

Cooling system expansion and technical knowledge

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 return lines, main hoses, or connection fittings, check the available parts in the Mercedes cooling system hoses and lines category.

To better understand how properly selected components – including used hoses and parts interacting with the radiator – affect engine thermal safety in high temperatures, it is worth reading the guide "Summer heat vs. cooling system: used radiators and fans as a guarantee of savings", which discusses the practical aspects of operating and optimizing the cooling system.