[JRTJH]

Reading the responses to the OP's problem and rereading the OP's first post, he says, " The last 2 years we have really struggled with freeze ups of the a/c." Looking at that part of the post, I'd suspect it's not a Freon leak. If it was a leak, there probably wouldn't be a 2 year history of the problem. With the small amount of Freon in rooftop air conditioners, even a "very small" leak would have stopped all cooling capacity in 2 years... So, my guess is that it's something else. Either low air flow, probably coupled with high humidity, inability to move air through restricted ducting (again, low air flow), dirty filters, leaking air box (hot air mixing with cold air in the hot air return) or the freeze sensor.

I haven't seen an A/C that works properly when new and leaks Freon to a point, then stops leaking for 2 years. My experience has been that once a leak starts, even a "minutely small leak" will empty the entire system and stop all cooling within 3-6 months.

Maybe I've had a "sheltered life" and I admit I haven't seen it all, but I don't think this is a Freon leak. The only "real way" to test it is with an ammeter and check the load on the compressor. But, I'd strongly suspect it's not a Freon leak.