[Ozarkguy]

OTod, have you done the soap bubbles (make some out of a bubbly dish soap) in a pump sprayer?  If your propane tank is original it could be leaking or the gauge or fittings. Close the valve and start spraying the tank and all the plugs and fittings.. Then work out from there...  Moisture can collect in the tank and cause pinholes as well as the lines over the years...