1993 Mercedes Benz 400sel

Air Conditioning problem
1993 Mercedes Benz 400sel V8 Two Wheel Drive Automatic 187000 miles

Had system fully charged. Die was put in and checked with ultra violet light. After two weeks air went hot again. Someone said it might be an evaporator under the dashboard that could not be seen that is slowly leaking. What do you think?
July 5, 2010.

Yes that it possible, now what I would do is ask the shop to put in one can of freon and use a sniffer (this tool sniffs for freon) put it in the most center vent and if it pick up freon it will sound off a beep indicating there is a leak inside, this could be the evaperator or the hoses to it or ? you won't know till you get into it then look for the die ot determine what it is. Here is a pic of the tool I am refering to.

Jul 6, 2010.