Yes, there's an O-ring. Spray some window cleaner on it and see if it bubbles. If it does, there's your leak.
order the replacement from Lindsay and have a competent tire shop replace it....what tires? Discount Tire replaced mine free cuz i have michelinsAlready sprayed soapy water on it, too slow of a leak to see...~2lbs in two days....well, hopefully I didn't overtighten it and break the fugin thing, If I didn't I'll bring it by the dealer and have em replace the o-ring....thanks guys.