Performed ac maintenance on both the trane main system. 5 ton r22 from 2005. Noticed that the evaporator coil had oil stains and was rusted. Performed electronic leak search, leak detector sounded off on the indoor coil at multiple spots. System is still operating at this time. Multiple small leaks. Let homeowner know to start preparing for system replacement. The other system services the detached shop behind the home. That system is cooling great. Washed out both condenser coils. Replaced air filter