I used some silver bearing soft solder to add shut off valves and hot gas bypass
regulators to a York dual evaporator coil chiller that had broken one coil. The chiller was installed about 1987. It has been about fifteen years since I made the repair. Some of the fittings have an oil drip but nothing showed up using a commercial soap solution for leak checking. I know it would have been better to use high temp solder. Do I have to try to use high temp solder over these fittings? It does not seem to loose much freon but it must be losing some. Would resoldering them with low temp solder buy some more years for the system? There are very many fittings with low temp solder. Is this the typical result for not brazing the fittings? What can I do to fix this situation besides trying to rebuild the whole system again?