This hose leaves from the 4 port bleeder housing (left lower port) on the firewall, runs along the left side of the motor, and attaches to the upper feed port on the water pump/thermostat housing. Obsolete by VW so we fired up the chemistry kit and are now having these made better than the originals. These are aircraft grade silicone hoses that are more durable and capable of withstanding temperatures far higher than the stock ones.