BMW F10 F11 LCI Diesel B47 518d 520d Hose Expansion Tank Pipe Line 8571803

BMW F10 F11 LCI Diesel B47 518d 520d Hose Expansion Tank Pipe Line is an original cooling system component designed for BMW 5 Series diesel engines after the facelift. It ensures a stable connection between the expansion tank and other components, which translates into safe engine operation and proper coolant circulation. This solution is dedicated to users who expect factory-fit quality and compatibility with the vehicle's design.

Specifications and technical data

• SKU: 8571803
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8571803
• Substitutable numbers: 17128571803, 8571803
• Fuel type: Diesel
• Category: Hoses, Lines & Pipes

Purpose and function in the cooling system

The coolant expansion tank hose in BMW F10 and F11 LCI models with B47 engines in 518d and 520d versions is responsible for transporting coolant between the tank and the rest of the system. A properly selected component helps maintain stable pressure and fluid levels, which is crucial for the durability of the Diesel engine and protection against overheating during city and highway driving.

The appropriate geometry and diameter of the hose are matched to the factory BMW cooling system, which reduces the risk of leaks, airlocks, and improper operation of the thermostat or water pump. As a result, the cooling system maintains parameters close to factory specifications, and the engine operates within the optimal temperature range.

Construction, fitment, and installation

The item belongs to the Hoses, pipes, and lines category, meaning it was designed as part of the coolant transport system. The hose construction is adapted to the BMW F10/F11 LCI engine bay, taking into account routing along factory mounts and proximity to other components. This facilitates installation and allows for maintaining the original routing of the system.

As a part originating from BMW, the hose ensures compatibility with factory spigots and connectors, minimizing the need for additional modifications. When replacing, it is recommended to:

• check the condition of the clamps and replace them with new ones if necessary,
• check for leaks after the first engine start,
• bleed the cooling system according to the service procedure for the specific model.

Benefits of using an original BMW hose

Using a hose dedicated to the BMW F10/F11 LCI with a B47 engine brings a number of practical benefits. The most important include:

• Factory fitment – compatibility with the engine bay geometry and original mounting points.
• Cooling system consistency – the hose works seamlessly with the stock expansion tank and other system components.
• Reduced risk of leaks – the correct shape and diameter contribute to a stable seal on the connectors.
• Trouble-free Diesel engine operation – proper coolant circulation supports maintaining the correct operating temperature of the B47 unit.

This solution is particularly recommended when replacing a damaged, brittle, or leaking hose, especially if you want to maintain parameters close to factory standards without experimenting with aftermarket replacements of uncertain fitment.

Part condition and service application

The offered hose is a used part, making it an attractive option for service repairs where a reasonable balance between cost and compliance with original BMW specifications is important. It works well both for typical replacement of a worn hose and for larger cooling system repairs, e.g., after a water pump failure or expansion tank replacement.

If you are planning comprehensive cooling system maintenance or are looking for other items from this group, it is worth browsing the entire offer in the Hoses, pipes, and lines for BMW category to select components from one consistent line of parts.

Additional technical information and support

Before purchasing, it is recommended to compare the engine configuration and body version with the data of your facelifted BMW 5 Series to ensure that the hose will work properly with your cooling system. In case of doubts regarding part selection, information about the brand, OEM part number, interchangeable numbers, or fuel type presented in the technical specifications section may be helpful.

If you are also interested in issues related to the durability of BMW engines and want to better plan your car's service, check out the guide: Emergency BMW E90 engines – check what can burden your service budget. For a broader perspective on operation and part selection for BMW models, you can also use other materials in the blog section, including the article A practical guide to selecting BMW parts for durability and cost, which will help you better plan future repairs.