Things You'll Need
New cooling unit
RV refrigerators are a major convenience when you're on the road, but repairs can be costly. The smell of ammonia in your RV or yellow stains coming from your RV refrigerator indicate a leak in your refrigerator's main component, the cooling unit. The only way to fix an ammonia leak is by replacing the cooling unit entirely. While RV refrigerator cooling units are a major expense, it is possible to save money by doing the installation yourself.
Remove the refrigerator from the RV refrigerator cabinet and set it upright. Wipe up any ammonia spills with a damp rag. Take off the back cover by removing the screws on the evaporator fins and the burner assembly cover with a Phillips-head screwdriver.
Set the refrigerator on its front, so that the exposed cooling unit faces up. Take out the old cooling unit and remove all of the dried thermal mastic remaining in the refrigerator box.
Shape the foam encasing your new cooling unit, using a wood rasp. Slide the new cooling unit into the refrigerator box to make sure that it will fit correctly. The fins should be flush against the evaporator tubes. Once you've achieved a proper fit, pull the new cooling unit out of the refrigerator box.
Open the bag of thermal mastic at one corner, using scissors, and squeeze the bag to apply thermal mastic in 1/2-inch increments to all of the exposed tubes.
Seat your new cooling unit in the RV refrigerator box carefully. Press down on the cooling unit with medium pressure for one minute to allow the thermal mastic to adhere the cooling unit to the refrigerator box. Screw down the top, sides and fins with a Phillips-head screwdriver. Set the refrigerator upright, and place it in the RV refrigerator cabinet.
Seal gaps between the foam and the refrigerator box with silicone caulk.
Ammonia can damage your eyes. Always wear safety glasses when replacing an RV cooling unit.