I have an old Holiday Rambler that was factory equipped with dual fuel (gasoline/propane). Parts of the propane system had been removed or damaged before I got the motorhome so I decided to just remove the whole thing. I thought it was just a simple matter of disconnecting propane lines and removing the regulator that was behind the front tire. However, I discovered that when I cut through one of the hoses, I got engine coolant running out. I then wondered what have I done. Soooo I tried a search on iRV2 forum, rv.net forum, and Airforums. Didn't find any information on the first two, but found just what I needed on Airforums. Seems someone had done the very same thing on an Argosy and I found out that there is an evaporator that is heated by the engine coolant. So, I hadn't cut into something I shouldn't have. I feel a lot better now. I never thought there would be engine coolant as part of the propane system. Thanks Airforums for putting my mind at ease.