Rein EPK0235 Engine Coolant Reservoir - Radiator

Engine Coolant Reservoir for BMW Applications

The Rein EPK0235 engine coolant reservoir is a direct-fit replacement for select BMW radiator cooling systems. Built from black plastic and supplied with a twist-on cap, it is made for drivers replacing a cracked, leaking, or discolored coolant expansion tank on supported BMW 2 Series and 4 Series models, as well as select 3 Series variants.

• Engine coolant reservoir for radiator cooling system service
• Black plastic construction
• Twist-on cap included
• No mounting hardware included
• No mounting brackets included
• Rein part number EPK0235

Fitment and Cross Reference

Compatible with BMW 230i, BMW M240i, BMW 430i, BMW 440i, BMW 330i, and BMW 340i applications listed below. This part cross-references URO (e.g., 17138677649) for the same application.

• Fits 2017-2021 BMW 230i, radiator, w/Cap
• Fits 2017-2021 BMW 230i xDrive, radiator, w/Cap
• Fits 2017-2021 BMW M240i, radiator, w/Cap
• Fits 2017-2021 BMW M240i xDrive, radiator, w/Cap
• Fits 2017-2020 BMW 430i, radiator, w/Cap
• Fits 2017-2020 BMW 430i Gran Coupe, radiator, w/Cap
• Fits 2017-2020 BMW 430i xDrive, radiator, w/Cap
• Fits 2017-2020 BMW 430i xDrive Gran Coupe, radiator, w/Cap
• Fits 2017-2020 BMW 440i, radiator, w/Cap
• Fits 2017-2020 BMW 440i Gran Coupe, radiator, w/Cap
• Fits 2017-2020 BMW 440i xDrive, radiator, w/Cap
• Fits 2017-2020 BMW 440i xDrive Gran Coupe, radiator, w/Cap
• Fits 2017-2019 BMW 330i GT xDrive, radiator, w/Cap
• Fits 2017-2019 BMW 330i xDrive, radiator, w/Cap
• Fits 2017-2019 BMW 340i GT xDrive, radiator, w/Cap
• Fits 2017-2018 BMW 330i, radiator, w/Cap
• Fits 2016-2018 BMW 340i, radiator, w/Cap
• Fits 2016-2018 BMW 340i xDrive, radiator, w/Cap

What This Reservoir Helps Address

• Coolant loss from a cracked or aging expansion tank
• Low coolant warnings caused by reservoir leakage
• Visible coolant staining around the radiator tank area
• Cap sealing issues on the existing reservoir
• Cooling system service on BMW 230i, M240i, 430i, 440i, 330i, and 340i models

Installation Notes and Tips

Verify the reservoir shape, cap style, and mounting points against the original unit before installation. Transfer any required sensors or hoses from the original assembly if your vehicle uses them, and inspect the surrounding cooling system for cracks, hardened hoses, or contamination before refilling. Bleed the cooling system according to BMW service procedures after installation.

Quality Assurance

Rein cooling components are built for OE-style replacement use in BMW radiator cooling system repairs. The EPK0235 is a focused replacement part for supported BMW applications, with fitment defined by the vehicle listings above.