My ac blowing hot air and my canister stay warm

A system will only drop temp about 20 degrees from outside temp. I would have then recheck the Freon level again. To much is as bad as to little when it come to Freon. Also the oil level can be to high causing the same thing. When they changed the compressor they should have also replaced the dryer and the orfice tube/screen. If that wasn't don't you could have a obstruction in line.

Orfice tube could be clogged. Have the low and high side checked.

Check that the heater is turning off as the hot air will over come the cool air. Check that the clutch on the a/c pulley is still engaging as it the unit was over filled or has a leak from a badly fitted pipe the high low switch will not allow the compressor to work.. If the work was done professionally check that the correct gas was used and seek warranty for the problem.

Yes. When you turn on the compressor via clutch Suction line pressures at around 3000 rpm should be around 30 PSI. If pressure stays high it is because the compressor is running but it is not doing squat and needs replacement - bad reed valves.

What do you mean when you say it wont shut off? is it blowing hot air or do you just feel a lite flow of hot air even if you have the settings to cold?

If this is the problem that you always feel hot air at low flow and the ac goes to hot air then i would say one of two things, first if you have the selector to cold and you feel hot air then there may be a problem with the blend door, this door move to allow hot or cold air, the door may be broken or just a bad motor that controls it. keep in mind if the ac system shuts down for any reason the air then will be warm, it will be about the same temp as outside and maybe a little hotter.

this problem almost sounds like the ac compressor shuts off and then you are getting the outside air which is hot, there are many reasons for the compressor to shut off, it could be the compressor clutch heating up and disengaging , this would be due to a bad compressor clutch.

another reason is the fans are not working, the best thing to do is when the system starts to blow warm check and see if the compressor is running, start engine and look at the front of compressor, with ac off the front of it will not move, and then with ac on the front will spin, check it out and let me know, if it blows warm air and ac is not working then it may be compressor problem but if you are getting warm air and the compressor is spinning then it may be a door problem.

This is hard to check with out testing the system, so i listed a few things to check and let me know the out come. also the ac blows cold for how long before it gets hot air blowing out of the vents, good day.

the orfice tube could be bad, that is a good place to start

Did you change the Receiver/ Drier and the Orfice Tube/ Expansion Valve? The Receiver/ Drier takes moisture out of the system and the Orfice Tube/ Expansion Valve controls the Hot/ Cold air. If that is bad it may not be opening or closing fully which would not let your A/C get as cool as it supposed to.

I would check the following possibilities:
1. Is compressor clutch working? - You need to do this when the ac is blowing hot air only - locate compressor drive pulley on engine - rubber belt wraps around it. Start engine and set to max ac. When the ac is blowing hot air, look at the center of the compressor drive pulley using a good flash light - watch it for a while, it should be spinning with the pulley - this means the compressor is engaged. If not, the compressor is not engaged. If your ac is blowing hot air, then the compressor should be engaged and running (trying to cool). If it is not engaged, then your compressor clutch is probably going out. Could be low voltage to clutch, but more likely the clutch is worn out and only working some of the time. Note: if working normally, the compressor clutch will engage and disengage in cycles- but the air should always be cold. If clutch is bad, compressor would need to be replaced (sold as one unit). This is tricky to diagnose and could take some time - you need to do it when ac is blowing hot air but set to max cooling.

2. Low on refrigerant or refrigerant has moisture in it? If your ac blows cold initially after being off for a while, then heats up, and continues to regularly cycle back and forth between hot and cool air, then the system may be low on refrigerant or the refrigerant may have moisture in it that is freezing and restricting refrigerant flow. An a/c shop can check refrigerant level and even replace refrigerant if moisture is suspected.

Could be other issues, but I would start with these.

Good luck

orfice tube stoped up or make shure motor electric fan comes on when u cut ur ac on with motor runing

when it gets warm , open the hood and watch the ac compressor , is the clutch still engaged and the front of ac compressor spinning , is the large tube out the back very cold , the other tube should be hot or warm.
if the air is warm but the ac is working correctly under hood then you have a issue with the vacuum controls on the inside of car.