2005 Fleetwood Excursion 39J bedroom slide. How far out should the bedroom slide, slide out? Measured just shy of 18". There appears to be a 1/2" - 3/4" gap between the seals or gaskets all the way around the perimeter of the slide. I am assuming the slide is supposed to come out 20" with the gaskets/seals compressed but I can't find any documents or literature to give me that information.