I've an old 74 C10 that runs on propane but recently I've had no luck getting the tank filled. Taken to multiple stations and no joy. Hose at the fill stations just spew gas out the sides. I tried yesterday morning when it was 50 degrees, so sure the tank isn't too hot. I'm also certain the tank is not full. Maybe fill valve (gasket it pristine), but not really sure. Does anyone know anywhere that can service this tank?