-Performed CMA Full Service on 1 rooftop gas package unit. -Cleaned return vents. Found no air filters on system. Performed extensive cleaning of evaporator coil and blower wheel. -All amperages, capacitors, and temperatures test good. Condensate drain pan heavily corroded and evaporator coil in poor condition. Compressor and gas burner compartments glued shut and sealed with silicone prior. -System is 2003 R22 type refrigerant and is in overall poor condition. System replacement should be considered. Office should provide proposal for replacement.