Q&A

 Master

It will be necessary to attach pressure gauges to the air conditioning system to verify the pressures. If you had to top up the system with refrigerant the system has a leak and the system should be evacuated and the leak repaired.
There is a commercially available refrigerant that has dye in it. You add it to the system if there is a leak the dye stains the area of the leak possibly enabling the leak to be found.
If you get a friend to start the engine and turn on and off the air conditioning do you hear the air conditioning compressor cycle on and off?