Residential service call for a customer in Celina and upon arrival Checked refrigerant levels on the 2 ton and 4 ton units. Both were low. Visual inspection was done on the indoor and outdoor units. Both coils on the indoor units contained rust, and visual oil spots were present. I sprayed the spots in question with soap water and confirmed there is a leak in Both coils. Customer requested a estimate for the coil replacements and 2ibs of refrigerant was added to the 2 ton unit. 4ibs was added to the 4 ton unit.