frig cooling problem...with a Norcold 821

dougraier, my camper was always parked level when the frig was ON ! What I dont understand is that when It became less efficent (propane heat always running and with a good flame) we turned the frig off for a couple of hours, then i turned it on and off for a couple of times, it returned to cool with a good efficiency, for 3 days.! Then it started to become less cold ,and we then took the habit to turn it off for a couple of hours and started again, and this seems to be the only way to get it back to cool normally!. The last summer when this appened, we were parked for 75 days. When we left to get home with the camper a distance of 200miles, ,the frig seems to cool normally. Before replacing it , how about taking it out of the camper and turning it upside down for a couple of weeks? What would you suggest me to do with this unit that still looks like new? how and what is the best way to "rotate" a frig? .The only time this frig is not level is when the camper is parked for the off season in my backyard! Thank you every one for your advices...