My 2003 Dutch Star will leak down in 5-7 days without the jacks down obviously. It goes down front end first and then the rear will go several days or up to a week later. I have found that the ride height valves have caused this in the past. It just hasn't been enough of an issue that I feel the need to replace them again.
Just a suggestion for those who need to replace ride height valves. It isn't difficult to do and you should search out the part number for the valve needed. Spartan supplied me the number. Part number or old valve in hand, go to a truck parts supply house and buy the valve. I saved nearly $100 per valve compared to my dealer or Spartan direct just on the parts.