Hello I have a 1990 f150 4.9. The ac on it never worked ever since I bought 2 years ago. It had the old school r12 gas and I bout a conversion kit that comes with the compressor, orifice tube and another part. I took it to a shop that I take my other cars to. They installed the parts but told me that at first the ac was blowing cold but over time wasn't as cold. They told me that there could be a blockage, the pressure switch could be bad, or I just need to drive for the freon to cycle. So I drove it to the gas station and I noticed the compressor was cycling more than it should. I pulled up the gas station and i heard gurgling coming from the radiator cap. The cap is good. But anyways the ac wasn't really pushing g put cold air anymore. I took back the shop and guy told me that it's either a blockage, or the sensor. He told me to keep driving and drive it hard. I drove it on the freeway and the compressor kept doing the same thing. It only cycles when I'm driving not as much when idling. I got to my girlfriends job and I noticed the temperature rising but didn't think much of it. I parked when inside for a little bit came put and my truck was leaking coolant from the reservoir. I could hear it gurgling too. My truck has never over heated before. It has a new radiator and I've flushed the system a few months ago. I dont know what could be going on. Buddy of mine said there could be a leak. I took the truck back to shop hopefully will get some answers but I'm just trying to help out the best I can.

 

Please, find another shop.!

 

Thats what im thinking of doing.

 

Was the other part the condenser? I don't know much about R12 conversions. If so I wonder if they removed the radiator to install it. If so maybe they didn't get the air out of the cooling system which could cause it to overheat. Or even if they had to disconnect a coolant hose for something and just topped off the reservoir leading to the same issue.