Rein EPT0021 Engine Coolant Reservoir

OE Quality Expansion Tank for BMW and Rolls-Royce

The Rein EPT0021 engine coolant reservoir is an OE-quality expansion tank built for direct replacement on select BMW 7 Series models and Rolls-Royce Phantom applications. It is produced from virgin plastic to help resist heat-cycle cracking and maintain reliable coolant system performance.

Key Features

• Produced from virgin plastic meeting or exceeding OE material specifications
• Resists cracking and wear caused by repeated heat cycles
• Direct-fit design supports straightforward installation
• Manufactured to strict engineering standards for material and dimensional accuracy
• Built for long service life in demanding cooling system conditions

Detailed Product Overview

Rein Automotive EPT0021 is an engine coolant reservoir designed to match the original expansion tank form, fit, and function on confirmed applications. It is a practical replacement for BMW 745i, 745Li, 750i, 750Li, 760i, and 760Li models, as well as Rolls-Royce Phantom vehicles, where a stable coolant reservoir is critical to maintaining proper system operation. The use of virgin plastic helps reduce the risk of premature cracking from thermal cycling, which can lead to coolant loss and cooling system faults. This part cross-references BMW OE numbers 17130152372 and 17130409581 for the same application.

Common Problems This Part Can Help Address

• Coolant leaks from a cracked or aging reservoir
• Loss of coolant caused by heat-cycle damage
• Visible plastic deterioration around the expansion tank
• Cooling system service needs on high-mileage BMW and Rolls-Royce vehicles
• Replacement of a damaged OE-style coolant reservoir

Installation Notes and Fitment

Fits 2004-2017 Rolls-Royce Phantom, N/A. Fits 2006-2008 BMW 750i, N/A. Fits 2006-2008 BMW 750Li, N/A. Fits 2003-2008 BMW 760Li, N/A. Fits 2004-2006 BMW 760i, N/A. Fits 2002-2005 BMW 745i, N/A. Fits 2002-2005 BMW 745Li, N/A. Verify reservoir shape, hose connections, and mounting points against the original part before installation. Proper cooling system bleeding and a pressure check after service are recommended to confirm leak-free operation.

Quality Assurance

Rein designs this expansion tank to meet OE-level material and tolerance requirements, using virgin plastic rather than regrind to improve durability under repeated heat cycles. The part number EPT0021 is engineered for direct replacement on the listed BMW and Rolls-Royce applications.