Compatible with: 2007-2012 Audi Q7 2004-2010 Volkswagen Touareg Package Includes: 1Pcs (Set) The function of expansion tank: It is used to store coolant that expands due to rising temperatures. It can also be used to add coolant. If the coolant is low, you can add coolant from the expansion tank. Symptoms of a broken expansion tank: 1. The return water (air) pipe from the upper water chamber of the water tank or the upper part of the thermostat to the expansion tank is blocked or not smooth. .
