Topran Coolant flange (top radiator) Jetta (1.4TSI)

The Coolant Hose Flange typically resides on the cylinder head and houses coolant hoses and temperature sensors. The flanges are typically made of plastic and due to age and constant thermal changes can become brittle over time and start to fail. If you’re noticing a coolant leak from around the coolant flange, it’s typically due to failure of the housing or the housing seal and should be replaced immediately. When replacing, it’s also a good idea and opportunity to replace any worn hoses and/or temperature sensors at that time.