Mercedes R231 Expansion Tank Reservoir Bleed Line Pipe Hose M276 A2315010925

Mercedes R231 Expansion Tank Reservoir Bleed Line Pipe Hose is an original cooling system component from the Lines, hoses and pipes group, designed for use in Mercedes vehicles with the M276 engine. It ensures stable coolant flow between the expansion tank and other system components, which is essential for maintaining the proper operating temperature of the powertrain.

Specifications and technical data

• SKU: A2315010925
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2315010925
• Substitutable numbers: A2315010925, A 231 501 09 25
• Part type: Pipe
• Category: Hoses, Lines & Pipes

Purpose and function in the cooling system

The presented water hose is responsible for the controlled flow of coolant between the expansion tank and the cooling system components in the R231 body with the M276 engine. A properly selected hose minimizes the risk of leaks, pressure drops, and engine overheating, which translates into stable engine operation across a wide range of loads.

Its original Mercedes origin allows for maintaining the correct hose routing geometry, connection diameter fitment, and compatibility with factory clamps and connectors. As a result, installation is predictable, with no need to modify other cooling system components.

Construction and installation fitment

The hose has been designed as an element dedicated to a specific engine and body configuration, which means it features the correctly selected length, shape, and bending points. Such a design limits material stress during operation and reduces the risk of rubbing against adjacent engine bay components.

The hose belongs to the Lines, hoses and pipes group, meaning it is part of the vehicle's fluid transport system. Proper fitment of this component is important not only for leak-tightness but also for the correct bleeding of the cooling system and maintaining stable operating pressure.

Condition and operational aspects

The offered water hose is a used item, which in practice means it comes from vehicle dismantling and may show signs of normal wear. This type of part is often chosen as an economical alternative to a new component, especially for routine repairs or restoring vehicle functionality after a cooling system failure.

Before installation, a standard visual inspection of the hose is recommended, including an assessment of material flexibility, the condition of the connection ends, and the outer surface in areas of potential contact with other components. A properly selected and functional water hose reduces the risk of coolant leaks and unplanned vehicle downtime.

Application in Mercedes service and repairs

Replacing the expansion tank water hose is a typical service operation performed during cooling system repairs, such as fixing leaks or replacing the expansion tank, radiator, or other hoses. Using an original Mercedes component allows for maintaining factory flow parameters and compatibility with other components.

In workshop practice, such a hose is installed as part of:

• fixing coolant leaks in the vicinity of the expansion tank,
• preventive replacement of rubber components in older vehicles,
• comprehensive cooling system repair after engine overheating.

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other elements from the same group, such as coolant lines, flexible hoses, or rigid pipes for operating media, check the available parts in the Mercedes Lines, hoses and pipes category.

Additional technical and operational information

When selecting a water hose for a specific vehicle, it is worth verifying compatibility with the engine configuration and production year using the manufacturer's catalog data. Proper fitment of the component reduces the risk of installation issues and ensures correct hose routing in the engine bay.

If you are interested in a broader context of powertrain operation in all-wheel-drive vehicles and the impact of individual components on operational reliability, it is worth reading an article comparing AWD systems – xDrive, 4Matic, quattro or 4Motion – a comparison of AWD drives from BMW, Mercedes, Audi and VW.