Coolant Expansion Tank

Product Details

The factory expansion tank is one of the most common failure points in modern BMW cooling systems, often failing along seam welds or developing micro-cracks around fluid quick-connect fittings. Replacing a degraded reservoir with this direct-fit Rein expansion tank restores pressure containment, ensures accurate coolant expansion volume, and prevents fluid loss before it turns into severe engine damage.

• Direct OE replacement engineered to exact dimensions for effortless installation using original mounting points and hose connections.
• Constructed from heat-resistant virgin plastic designed to endure severe thermal cycling and internal cooling pressures.
• Restores proper cooling system pressure to raise coolant boiling points and eliminate air pockets.
• An essential replacement component when refreshing aging cooling system hoses, water pumps, or radiators.

Prop 65 Warning

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Lifetime Replacement

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