THREE cans of stop leak? Did you read the instructions on the can? One can, followed by a can of r134a to keep the stop leak off the schrader valve. Then run the system for at least 30 minutes.

By the way, with stop leak added, let the AC service techs know so it doesn't ruin their machine if you ever have work done. Otherwise it will cost you a few thousand dollars to replace their machine.

If the evaporator is leaking, it will start to leak again because the fins have corroded so badly that it has become porous. Stop leak will slow down the degredation, but it is from the outside, not the inside of the evaporator.

The best thing to do now, is to check the temp at the side vent. Recirc on, outside vent off (center dash), and both dials at 60F. Rev the engine to 2K rpm and check the temp. If it stays above 60F at the vents and the outside temp is at 75F, then you need more r134a. Open the engine bay and check the temp of the AC plubming at the firewall. Both pipes should be cold and sweaty, if one is warm then you need to add more r134a.

If you over pressurize the system because it is cool outside, the system will blow the pressure valve on a hot day. Then you will hear a bang, followed by gree/yellow liquid on the ground under the engine. Ask me how I know. The valve will close by itself and your AC will work for a while longer. Mine went for 3 weeks before a recharge.

Oh, the receiver/dryer is probably full of stop leak by now.

Klaus
--
Common sense trumps a PhD