Came out to call for a system not cooling properly. We were out in June to find a leak. I was able to locate one and repair a small leak by the inlet on the suction line of the evaporator coil. Customer stated that it was working fine up until this week. I checked system and found it low on refrigerant again. Did another leak search and found another leak. It is located at the bottom right corner of the evaporator coil where it is severely rusted. This is a place that is non repairable. I made homeowner aware of the condition of the coil last time I was out, and the evaporator coil only had the 5 year standard warranty on it, and it was installed in 2015. Gave customer pricing of replacement of evaporator coil. Customer wanted to charge system for now and plane for replacement at a later date. Added 2lbs of 410a to system to get proper subcooling of 9.