Rein EPT0151 Engine Coolant Reservoir - Radiator

OE Quality Expansion Tank for BMW Cooling Systems

The Rein EPT0151 engine coolant reservoir is an OE-quality expansion tank built for BMW cooling system service. It is produced from virgin plastic to help resist heat-cycle cracking and maintain durable, long-term performance in demanding engine bay conditions.

• Produced from virgin plastic meeting or exceeding OE specifications
• Resists cracking and wear from repeated heat cycles to help prevent coolant loss
• Direct-fit design for straightforward installation
• Manufactured to strict engineering standards for materials and tolerances
• Rein OE quality expansion tank for BMW 535i, 535i xDrive, 640i, 740i, and related applications

Built for BMW Fitment and Cooling Reliability

Rein EPT0151 is an OE-style coolant reservoir designed for application-specific BMW fitment. It serves as the expansion tank in the cooling system, helping maintain proper coolant volume and system stability on vehicles such as the BMW 535i GT, 640i Gran Coupe, and 740Li. This part cross-references BMW 17137601949 and 17137806038 for the same application.

What This Expansion Tank Helps Address

• Coolant leaks caused by cracked or aging reservoir plastic
• Loss of coolant from heat-cycle damage
• Warning lights or low coolant level concerns
• Cooling system service needs on BMW 535i, 640i, and 740i models
• Replacement of a worn expansion tank during radiator or cooling repairs

Installation Notes and Fitment

Compatible With: Fits 2013-2019 BMW 640i Gran Coupe, N/A; Fits 2014-2019 BMW 640i xDrive Gran Coupe, N/A; Fits 2012-2018 BMW 640i, N/A; Fits 2014-2018 BMW 640i xDrive, N/A; Fits 2010-2017 BMW 535i GT, N/A; Fits 2011-2017 BMW 535i GT xDrive, N/A; Fits 2014-2016 BMW 535d, N/A; Fits 2014-2016 BMW 535d xDrive, N/A; Fits 2011-2016 BMW 535i, N/A; Fits 2011-2016 BMW 535i xDrive, N/A; Fits 2012-2016 BMW ActiveHybrid 5, Radiator; Fits 2011-2015 BMW 740i, N/A; Fits 2015 BMW 740Ld xDrive, N/A; Fits 2011-2015 BMW 740Li, N/A; Fits 2013-2015 BMW 740Li xDrive, N/A; Fits 2013-2015 BMW ActiveHybrid 7, Radiator. Verify the reservoir shape, hose connections, and mounting points against the original part before installation. Proper cooling system bleeding and refill procedures should be followed after replacement.

Quality Assurance

Rein manufactures this expansion tank to strict material and dimensional standards, using virgin plastic rather than regrind to improve durability and heat-cycle resistance. The result is an OE-quality replacement for BMW cooling system repair on applications including the 535i, 640i, and 740i. Part number EPT0151 is engineered for direct replacement service.