I've heard many stories both ways. My youngest who was still in teens when he first did it says it is easy. Others say have it done at a shop. Personally if it leaked or is not cooling I'd want to know why. I'd find a reasonably priced shop. Big help huh ? Recently added AC/heat to the 55 wagon and still need to have the hoses crimped and the system charged. Prices don't seem too bad at smaller shops or even NAPA. Boy they get a lot of free advertising here.
Find a guy that knows AC units that doesn't think it's the most complicated thing on a car. Have him shoot you up WITH dye in the freon. Then look for the leak yourself. Chances are, on your car, it's a slow leaking pressure switch that goes for around 15 bucks and is easy to replace. IIRC, it's located on the side of the evaporator canister that sits ahead of the firewall on the passenger side. Look for dye there after running it for a day or so. If you see it buy the cheapest one you can find and install it. The AC units in your car are good units and don't often have big problems. The pressure switch is nothing more than a schrader valve in there and 9 times out of ten it's just the "O" ring. Probably just replace that and your troubles may be over....if you can find the right size "O" ring. For 15 bucks replace the whole switch, it comes with the "O" ring, if that's where it's leaking. It's often the culprit on these cars.
On ALL my GM cars with AC that no longer works, the leak is in the AC condenser. But hopefully for you it's just a pressure switch.
If it's still working just add some R134a as directions state. But get the freon with dye so at a later date if you have a laek it will be easy to detect with UV light and glasses.
