So I found a free 8000 btu window a/c on the side of the road today. It looked fairly new so I grabbed it to see what the issue with it is. The unit was made in 2018 per the sticker. I plugged in the unit and all the functions work fine and the compressor kicks on but the evaporator barely gets cold. Like if the ambient temp is 80 the evaporator may drop to 70. The unit takes r410a which i don't have nor do i want to try and bring to someone to recharge. My suspicion is that the unit is low on refrigerant. I have a manifold gauge set and a vacuum pump. I was thinking of buying one of those low side line piercing valves and trying to recharge the unit myself. I am having trouble finding info on the compatibility of r410a and r134a and if the oils are compatible etc. Maybe the charge is fine and there is an issue with the txv or orifice tube? I understand that r134a and r410a are quite different but the unit was free. Maybe we can pretend we are in the remote jungles of south america and i only have r134a. Is it possible to get the evaporator cold and the pump happy with r134a.