Once we were sure every nut, bolt, screw, clamp, and electrical fitting was not only tight, but also correct, we had the system charged with 1.8 pounds of 134A refrigerant by Ron Gimenez of Quality Air. We strongly recommend you use a professional automotive A/C specialist to charge your system, as it needs to be fully evacuated prior to charging to operate properly. Using the aerosol-style cans from the auto parts supply just won't cut it.