Two years ago, I had the AC system on the LeSabre recharged and it ran beautifully for two years, but this spring it has started to run warm again and no air conditioning cooling is happening now. They checked every part of the system when they charged it two years ago including opening up the wiper assembly. At the time, they could not find any leaks anywhere with either the die test or the leak detector. The shop that does this kind of work for me has now gone over the system again this week and they cannot find any leaks anywhere and are suggesting it could be the evaporator. Note that the evaporator is the only part of the system that is not easily accessible and the labour costs or couple of hundred dollars in order to get access to it. I can still find replacement evaporators for this system including an AC Delco version. But my question is, if I go forward and get the evaporator replaced, is there any other part of the system that could be leaking? They have checked every other part of the system including the compressor which is original and all else seems to be working just peachy. I am looking at about $250 labour to open up the old evaporator and then another $150 or so for the new evaporator. FYI, the leak must be extremely small because it took two years for it to impact the temperature of the air cooling. What would you do?