With the expansion tank being exposed to high pressures and temperatures, the plastic tank is known to crack and leak (particularly at the hose fittings). Without the correct amount of fluid in your BMW’s cooling system, your vehicle can overheat, causing expansive issues. With the high failure rate of ageing tanks, we recognise that the market has been flooded with notoriously cheap aftermarket replacements, which is why we choose to stock NRF tanks that are high quality and designed to last. This expansion tank includes a brand-new coolant level sensor and bleed screw.