A/C toubleshooting on 1990 Cadillac DeVille

I have replaced my compressor recharged my refrigerant and my 1990 cadillac deville still blows hot air

Asked by for the 1990 Cadillac DeVille
Did you hook up a vacuum pump and remove all the oxygen from the system? If not you will need to have a shop pull a vacuum and refill with the proper amount of freon or get a price for recharging the system here and find a shop here