BMW X5 E53 4.4L ENGINE 2004-2006 COOLANT RECOVERY EXPANSION TANK NEW PART# PCF000033 How do I know if my radiator overflow bottle needs to be replaced? Since radiator overflow bottles are plastic, theyre usually replaced due to cracks. Wild temperature swings (think cold winter day and high temp engine coolant) can cause the bottle to split at its seams. Another common reason for replacement is broken mounting tabs or hose outlets from debris or other repair work. If you pour coolant in and can see it running out, chances are the bottle needs to be replaced. Can I replace a radiator overflow tank myself? Yes! Make sure to wait until the car has cooled down first, though. In most vehicles, installation is as simple as disconnecting the coolant hose, unbolting any mounting hardware, and swapping it out with a new one. On some models, there may also be a coolant level sensor in the tank that will need to be removed from the old bottle and inserted into the new one. BMW X5 E53 4.4L ENGINE 2004-2006 COOLANT RECOVERY EXPANSION TANK NEW COMES WITH LEVEL SENSOR EXPANSION TANK CAP DOES NOT INCLUDED