Fit For: 1999-2000 BMW 528i 2001-2003 BMW 530i 2001-2003 BMW 525i What is a Coolant Tank: It is typically connected by a tube to the radiator filler neck, and can serve as a place for excess coolant to be captured when the pressure release valve in the radiator cap gives way. In a properly operating cooling system, the coolant will then be siphoned back into the radiator as the temperature drops. Features: .
