I know this truck is old but I bought it new and it still runs great with well over 250,000 miles on it.

About 10 years ago the AC give me problems similar to what I have now. I replaced the expansion valve and drier, put the R12 back in it and all was well until a few days ago. Yesterday the vent temps were in the 70's. .

I connected my gauges and the low side will go south when I give it the gas and the high side goes to 250 #'s. The low goes from around 30 psi at idle to half that when giving raising the rpm's . It is also hot and humid where I live.

This morning I got in the truck after sitting overnight I noticed the temp was at 40 degree and it was working fine. When I got back home the vent temp was around 50 and going up.

I again connected the gauges and same reading. It starts blowing hot air. At idle the gauges read 200 on the high side and 30 on the low side at idle but no cold air. I accelerate and the high goes to a little over 250 and low back down to around 15.

Am I looking at expansion valve problems again ? I know I lost a little Freon when I connected the gauges and caught it before too much got out. It is showing air in site glass on the drier now but I don't have but one can of R 12 left and don't have a recovery machine. I think I can get enough R12 from a friend who does ac work.. He told me last month he has a 30 pound can of this.

I don't really want to convert it to 134 because when I used to mechanic years ago I did this type thing and never got the vehicles to cool as good as using R12.
The compressor seems to working fine and is nice and quite. It will cut off when the high side goes above 260 plus or minus and few PSI's. but kicks back on when it drops back to around 200 psi.
Any tips will help. I still love to drive this old truck even though I just bought a new Toyota Tacoma TRD sport