Safety has to be of primary concern when working with propane. If you do any work at all on the propane system, you need to test it, and you need to test it in a safe manner. Before you test your work, read and follow the safety tips below. In fact, it would be a good idea to check the propane system for leaks even before starting work on it. You don't want any surprises. If you have to disconnect any electrical power to work on the propane system, be sure to reconnect it after the repairs, and before re-supplying propane to the refrigerator to avoid any inadvertent sparks later
The first step in working safely with propane is having complete control of it. You have to be able to stop the flow of propane immediately if there is a problem. Sometimes having access to the on/off valve at the back of the refrigerator will suffice. Other times, a second person inside at the controls of the refrigerator or at the shut off valve of the propane tank is necessary.
A soapy solution of a little liquid dishwashing soap and water is good for testing for leaks. It's recommended that you use a dishwasing liquid that doesn't contain ammonia, since ammonia tends to deteriorate brass. This solution can be squirted on to the gas fittings, or brushed on. If a fitting or component begins to bubble, there's a leak. NOTE: A very large leak such as a hole may not bubble -- the solution is just pushed away by the gas pressure.
If you have electronics on your refrigerator, be careful not to squirt the soapy solution on to them. In fact brushing the solution on may be better. Also, if you get the soapy solution on the spark electrode or electrode wire, they will be temporarily shorted out and will not function until they dry.
Know and understand the components of the gas system. As an example, if you knew that no propane passes the safety valve until the plunger is depressed, you would realize that soap testing the fittings after the safety valve without depressing the plunger would be pointless.
When replacing parts, always use Teflon tape on pipe thread fittings. Do not use Teflon tape, or any other thread sealer, on the threads of flare nuts or compression fittings. These connections make their own seal.