VW Fox expansion tank hose. This hose runs from the expansion tank to the radiator. Coolant hoses rot from the inside out, so it’s hard to tell if they are bad before it’s too late. If you find yourself replacing the expansion tank it would be a good idea to replace this when you install a new expansion tank.
The VW Fox expansion tank hose is a common failure part. When you replace this part make sure to inspect your expansion tank for buildup where this hose connects. If there is a large build up you may not solve your leaking problem. Also make sure you are using the VW approved coolant in your engine, for long life and maximum protection.