Rein CHE0540 Engine Coolant Hose - Expansion Tank (Upper)

OE-Style Coolant Hose for BMW Cooling Systems

The Rein CHE0540 engine coolant hose is an OE-quality replacement for European cooling systems that need the same fit and routing as the original part. It is built for BMW X3 and BMW X4 applications with the upper expansion tank connection, making it a direct replacement for the factory hose assembly.

With matching 0.969 in. outside diameters at both ends and 0.441 in. inside diameters at both ends, this hose is sized to maintain proper coolant flow and secure connection points. The Rein CHE0540 is a practical choice for BMW X3 and BMW X4 owners looking for a replacement that follows OEM dimensions and connector style.

Key Features

• Engine coolant hose for the upper expansion tank connection
• Outside diameter: 0.969 in. at hose end 1 and hose end 2
• Inside diameter: 0.441 in. at hose end 1 and hose end 2
• OE-quality replacement for European vehicle cooling systems
• Direct replacement design for factory hose routing and fit
• Rein CHE0540 part number for easy identification

Detailed Description

Rein Automotive designs this coolant hose to match the original manufacturer’s hose shape, branch sizing, and quick-connect style used on OE assemblies. The CHE0540 is made for the upper expansion tank position on 2011-2017 BMW X3 and 2015-2017 BMW X4 models, helping restore the factory-style coolant path without altering the system layout. If you are replacing a worn BMW X3 coolant hose or a BMW X4 upper expansion tank hose, this part number CHE0540 provides the correct OE-style dimensions for the application.

This part cross-references BMW 17127601850 and 17127601859 for the same application.

What It Helps Address

• Coolant seepage at the upper expansion tank hose connection
• Cracked, hardened, or swollen hose material
• Loose or poor-fitting hose ends caused by wear
• Cooling system leaks that trigger low coolant warnings
• Loss of proper coolant circulation through the expansion tank line

Installation Notes and Tips

Verify the hose end diameters and the upper expansion tank routing before installation. Inspect the mating connectors, clamps, and nearby plastic fittings for wear or damage, and replace any compromised components before refilling the cooling system. After installation, bleed the cooling system according to BMW service procedures to remove trapped air.

Quality Assurance

Rein Automotive positions this hose as an OE-quality replacement for European vehicles, with dimensions and connector design matched to the original assembly. The CHE0540 is built to follow the factory fitment used on BMW cooling systems.