Bleed Hose Mercedes W177 Coolant Expansion Tank To Radiator Line A1775011801

Bleed Hose Mercedes W177 Coolant Expansion Tank To Radiator Line connecting the expansion tank to the radiator is a precisely shaped cooling system component, designed specifically for this generation of compact Mercedes models. It is responsible for stable fluid discharge and return, which promotes uniform system operation and reduces the risk of engine overheating. Choosing an original hose from this group ensures proper routing of the cooling medium and a secure fit to factory mounting points.

Specifications and technical data

• SKU: A1775011801
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1775011801
• Substitutable numbers: A1775011801, A 177 501 18 01
• Category: Coolant Hoses

Function of the hose in the Mercedes W177 cooling system

The hose connecting the expansion tank to the radiator in the Mercedes W177 operates in a critical area of the cooling system. It is responsible for:

• stable discharge of excess coolant to the radiator,
• maintaining the correct fluid level in the expansion tank,
• assisting in system bleeding after service or fluid replacement,
• maintaining the proper operating pressure in the cooling circuit.

Thanks to its appropriate shape and diameter, the hose works with the factory water pump and radiator, which promotes stable engine operating temperature and reduces the risk of localized overheating.

Original fit and construction

The hose belongs to the Cooling system hoses and lines group, which means it has been designed for specific mounting and routing points in the Mercedes W177 engine bay. In practice, this translates into:

• secure fit with the expansion tank and radiator connectors,
• proper routing along factory brackets and clips,
• maintaining required bending radii without the risk of kinking,
• compatibility with original clamps and connectors.

Such a fit reduces hose stress, minimizes the risk of leaks, and facilitates service, which is particularly important in modern, densely packed engine bays.

Used condition and service benefits

The item is offered in used condition, which represents a reasonable compromise between repair costs and maintaining the manufacturer's original specifications. In practice, this means the possibility of:

• reducing service costs while maintaining factory fitment,
• replacing a worn or damaged hose with a component of proven geometry,
• avoiding problems with imprecise aftermarket replacements of different stiffness or diameter.

Replacing the hose in this area of the cooling system is recommended especially when signs of leaks, rubber cracking, or problems with bleeding after fluid replacement appear.

Thermal safety and cooling system diagnostics

A properly functioning hose between the expansion tank and the radiator has a direct impact on the safe operation of the cooling system. Leaks or deformations in this area can lead to:

• a drop in coolant level and air in the circuit,
• incorrect temperature readings,
• accelerated wear of cooperating components (water pump, seals, radiator).

If you want to better understand how individual components – from hoses to radiators – affect the durability of the power unit, it is worth checking out the guide Engine cooling system – overheating, repair, and used radiators, which discusses practical aspects of diagnostics and service.

Expanding the cooling system in a Mercedes

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 additional hoses, return lines, or radiator supply lines, check out the available parts in the Mercedes cooling system hoses and lines category.

Summary

The hose connecting the expansion tank to the radiator in the Mercedes W177 is an essential element ensuring proper coolant circulation and stable engine operating conditions. By choosing an original component from the Cooling system hoses and lines group, you gain a secure fit, proper geometry, and a solution consistent with the factory design of your Mercedes cooling system.