the air conditioner blows warm air 1 day after check and new fre-on

I really don't care what the so called machine shows, you have a leak. Most likely the evaporator. If you have more questions contact me at autoknowhow@gmail.com

Could be something as simple as a defective service port. We see a lot of "no leaks detected" vehicles, but as soon as the machine is removed- a leak is noted. Could be a service port valve having a faulty seal, could be an evaporator (but machine should have picked up a leak of that size). Could be failing compressor- we would have to inspect/test to properly advise you on the appropriate repairs.