A/C coolant leak when compressor clutch engages?

On the 2nd A/C issue I had on my dad's 93, I had a restriction somewhere that didn't let enough through on the low side. I had believed at first that it was a leak, tried to just top it back off, and ended up overfilling the system causing the pressure relief valve that is on the fitting that attaches to the compressor to release some freon. Was easy to see the wet spot it caused next to it and was a noticeable leak you could hear. Only way to confirm was to hook up gauges to the high side as well and see it was in excess of 400 psi.

Regardless the fix will be to open up the system (with recovering what freon is left, though there is no reasonable way to enforce you to do that), go ahead and flush your coils to be on the safe side while you have it open, replace/inspect the O-rings (since if it is a leak at the compressor it would most likely be an O-ring), and at least inspect the orifice tube while you have it apart, at minimum. It is always recommended to replace the drier whenever you open up the system though, but not always necessary. Of course if you are dealing with old hoses, it wouldn't hurt to consider replacing them as well to be able to delay any issues with them.