[thom4782]

Any good quality AC shop can do the necessary testing work. It's a two stage process.

First, they will fill the system with new refrigerant and a dye. If there is a gross leak, the shop's sniffer might be able to detect it right away. They'll need to be through though because there are many places where the refrigerant can escape.

Second, if there is no obvious leak, then you'll need to wait a few days or weeks until the AC system starts to blow warm air again. When this happens, the AC shop will use a UV light to look for dye throughout the system so it can find the source of the leak.

Here's a big diagnostic trick to keep in mind. If the evaporator is leaking from inside the sealed AC/heating box under the dash, have the AC shop peel back the passenger side carpet, pull the drain hose up and look for dye inside the hose. If it's there, the evaporator is leaking.

Good luck.

PS: My car started leaking when it hit the 10 year mark. I would not be surprised if that about the time people start seeing that the AC system needs repairs.