Fitment: 2008-2009 Hummer H2 2007 Chevrolet Silverado 1500 Classic 2007 GMC Sierra 1500 2007 GMC Sierra 1500 Classic 2007 GMC Sierra 2500 HD Classic 2007 GMC Sierra 3500 Classic For more details,pls check compatibility Chart. What is an expansion tank on a car? The expansion tank absorbs excess coolant and minimizes excess pressure in the engine cooling system. An expansion tank helps maintain a minimal pressure increase during heated water expansion, helps reduce coolant hammer, and helps protect the engine cooling system from stress. Features: .
