I'd recommend against using any stop-leak on it. It may plug the leak but it also could plug the expansion valve, condensor, receiver dryer (are you getting the point?). If the one shop you went to determined it to be the evaporator why not just bring it to another shop and don't necessarily tell them what the other shop said, just tell them you recently had some refrigerant added and now it is not cooling at all. Tell them you would like them to put dye (only not leak stopper) in it and find the leak then you will know if both techs independantly conclude it is the evaporator you will be pretty sure that is what is at fault. Just bite the bullet and have it fixed, don't mess around with band-aids, they cause more problems than they cure. Don't use a leak-stopper unless your goal is to get it working long enough to sell it...that's why used car dealers like that stuff.

If you are lucky they will find the leak is actually in the condensor and not the evaporator...the condensor is a MUCH easier part to replace. If it is the evaporator then $1500-$2000 is not unreasonable for parts and labor...in fact it is cheap.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz