I was driving my wife to the dentist and car overheated. Luckily i was right next to a gas station. It shut off right when i turned in so had to push it into the lot. Added coolant while it was running and it poured out of the top of the engine. Thought maybe a blown headgasket but turned out to be a short tube connecting the two metal nipples in the photo, about 10" length. Waiting for a new hose to show up.