YzusGomumu Coolant Reservoir Tank for BMW & Mini — Direct-Fit with Pressure Cap, Corrosion-Resistant

This replacement coolant overflow reservoir from YzusGomumu restores the cooling system’s ability to capture excess antifreeze as the engine warms and cools. Designed to match OEM mounting points and plumbing, the tank comes with a new pressure cap and is molded from corrosion-resistant material for a longer service life under typical under-hood conditions. Before purchasing, confirm compatibility using the listed part numbers and vehicle years.

Will this reservoir fit my BMW or Mini?

Compatibility depends on vehicle year and engine variant; this tank fits a range of BMW and Mini models when paired with matching part numbers. Check your vehicle’s service manual or the existing tank’s OE stamp to verify fitment.

• Compatible models include: 2018–2019 BMW 118i; 2018 BMW 318i; 2014–2019 BMW i3 and 2018–2019 i3s; 2014–2019 BMW i8.
• Also fits multiple Mini models: 2007–2015 Mini Cooper, 2011–2016 Mini Cooper Countryman, 2013–2016 Mini Cooper Paceman.
• Reference OE numbers: 17137539267, 603-332, 603332 to confirm exact match.

How does the YzusGomumu tank help the cooling system perform?

The reservoir captures expanding coolant and returns it to the system as temperatures drop, helping maintain proper fluid levels and reduce air intrusion. Using a correctly sized and sealed tank prevents spills and preserves system pressure for reliable cooling performance.

• Stores overflow coolant during thermal expansion and returns it via return hose when the engine cools.
• Maintains head pressure with the included cap to support boiling-point control and system balance.
• Sealed connections reduce the risk of leaks and air pockets that can impair heat transfer.

What are the materials and durability features of this replacement?

YzusGomumu uses reinforced, corrosion-resistant polymer designed for repeated thermal cycles and the vibration typical of engine bays. The robust construction resists cracking, swelling, and chemical degradation that can cause early failure in lower-quality tanks.

• Made from high-quality, heat-tolerant plastic to endure under-hood temperatures.
• Rugged design minimizes warping or stress-related fractures over time.
• Comes with a matching cap to ensure proper sealing and pressure management.

How easy is installation and what comes in the package?

Installation is straightforward for anyone comfortable with basic automotive maintenance; the reservoir uses the vehicle’s original mounting points and hoses. The package provides everything needed to replace the tank assembly and get the cooling system back in working order.

• Package includes one radiator coolant overflow reservoir tank and one cap.
• Designed as a direct-fit item—no custom modifications required on compatible models.
• Simple bolt-on swap: remove old tank, transfer or replace hoses, then install the new unit and cap.

Who is this for: This YzusGomumu replacement reservoir is intended for owners and mechanics servicing compatible BMW and Mini vehicles who need a reliable, OEM-style coolant expansion tank. It suits those replacing a cracked, leaking, or discolored tank, or anyone restoring proper cooling performance after overheating or system repairs. Always verify your vehicle’s model year and part number against the provided OE references before ordering to ensure a correct fit.