1984 245 AC Flush?

[VolvoPrince]

Hey guys, so for the last few months the temperature out in AZ has been creeping up, and I recharged it about 6 months ago. It doesn't leak and has been at a stable 35PSI on the low port since then. Since it's starting to heat up, though, I've noticed that I need to drive the car around for about 15 minuets before it really gets cold. And this is with the condenser fan on.

Is there any way I can fix this issue? It's only in the high 90's this week so I don't know what it will be like 100+! Is there a flush for the R134a or something? Or is it something else wrong with my system?

In addition to the charge, I've also done the fan clutch along with the rest of my coolant system (not AC), including head gasket, but I know if the engine is running hot that will affect the AC.