BMW 1 Series E81 E87 E87N Radiator Bottom Hose Pipe 116i N45 N45N 7526391

BMW E81 E87 Radiator Coolant Hose Thermostat is a cooling system component from the Hoses, Pipes & Tubes category, designed for precise coolant flow between the radiator and the thermostat. Original sourcing from the BMW group ensures correct geometry, appropriate connection diameters, and a perfect fit for factory-issued spigots on the engine and radiator.

Specifications and technical data

• SKU: 7526391
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 17127526391
• Substitutable numbers: 17127526391, 7526391, 12427793201, 7793201
• Category: Hoses, Lines & Pipes

Purpose and Function in the Cooling System

The radiator coolant hose to the thermostat is responsible for a stable, leak-free connection of cooling system components in BMW E81 and E87 models. A correctly selected hose:

• ensures proper coolant flow between the radiator and the thermostat,
• maintains the optimal operating temperature of the power unit,
• minimizes the risk of engine overheating and reduced cabin heating performance.

Thanks to its precise fit for the specific BMW platform, the hose maintains the correct routing within the engine bay, avoiding interference with other components and allowing for hassle-free installation.

Construction and BMW Fitment

As a BMW branded part, the radiator coolant hose to the thermostat has been designed with factory mounting and routing systems in mind. The appropriately selected material flexibility allows for engine unit vibration compensation while maintaining a stable shape under the cooling system's operating pressure.

The original geometry of the connections facilitates installation onto the radiator and thermostat spigots, reducing the risk of leaks and the need for additional adapters. This solution is particularly beneficial for vehicle servicing where maintaining the original cooling system configuration is important.

Condition and Service Application

This component is from the used parts category, allowing for an economical yet functional replacement of a damaged or leaking hose in your BMW E81 or E87. This type of component is often replaced preventatively during work on the thermostat, radiator, or during major cooling system repairs.

Selecting a hose from the same model family reduces the risk of installation issues and facilitates the maintenance of correct engine operating parameters after servicing.

Benefits of Using an Original BMW Hose

• Factory Fitment – Compatible with the BMW E81/E87 cooling system, no modifications required.
• Stable Fluid Flow – The correct cross-section and routing of the hose support even engine cooling.
• Hassle-Free Installation – Appropriately shaped ends and hose length simplify the mechanic's work.
• Economical Service Solution – A used part helps reduce repair costs while maintaining functionality.

Related BMW Hoses, Pipes & Tubes and Technical Knowledge

If you are looking for other BMW Hoses, Pipes & Tubes for your car, check out the BMW hoses, pipes & tubes available in our store to select a complete solution for your cooling system or other fluid installations. To expand your knowledge about the construction and servicing of premium cars, you can also read the article describing the evolution of Mercedes' flagship sedans – Evolution of the Mercedes S-Class: from W140 to W222 – Innovations and Service Parts, which illustrates how premium manufacturers design key components and systems in their models.