Rein EPT0274 Engine Coolant Reservoir - Radiator

Engine Coolant Reservoir Overview

Rein EPT0274 is an OE-quality engine coolant reservoir built for BMW applications that require a radiator-mounted expansion tank without a cap. It is made from virgin plastic to match original material standards and resist cracking from repeated heat cycles.

For BMW owners looking for a direct replacement coolant reservoir, this part is built to fit and perform the way the original system was intended. The black plastic construction and twist-on cap design follow the OE-style layout used on the vehicle cooling system.

Key Features

• OE-quality expansion tank construction for cooling system replacement
• Virgin plastic material helps resist heat-cycle cracking
• Black plastic housing matches the original-style appearance
• Twist-on cap design for the reservoir opening
• Built for radiator-mounted BMW cooling system applications

Detailed Description

Rein EPT0274 is an engine coolant reservoir for select BMW performance and luxury models, including the M850i xDrive, M850i xDrive Gran Coupe, Alpina B8 Gran Coupe, M550i xDrive, 750i xDrive, and Alpina B7. It is intended for radiator-mounted applications and is listed for vehicles without a cap. This part cross-references Monroe Shocks & Struts (e.g., 17135A7BC90) for the same application.

Rein Automotive positions this expansion tank as an OE-quality replacement that uses virgin plastic rather than regrind material. That material choice helps the reservoir maintain durability under repeated thermal cycling, which is important in BMW cooling systems where heat and pressure can stress plastic components over time. The part number EPT0274 is useful when verifying the correct reservoir for the application.

What It Is Used For

• Replacing a cracked or heat-damaged coolant reservoir
• Restoring proper coolant expansion and recovery function
• Addressing coolant loss from a damaged tank body
• Replacing a reservoir with worn or damaged cap interface
• Returning the cooling system to OE-style configuration

Installation Notes and Tips

Confirm the vehicle is listed with a radiator position and without a cap before ordering. Match the part number EPT0274 to the application details, and verify the reservoir style against the original unit before installation. Because mounting hardware and brackets are not included, reuse or source the required vehicle-specific components as needed.

Quality Assurance

Rein Automotive states that this expansion tank is produced to OE-quality standards and uses virgin plastic to improve durability and reduce cracking from heat cycles. The part number EPT0274 is built to follow the original manufacturer’s intended fit and function for the cooling system.