[Tech II]

Running for an hour, that oil dye should have left the system at the leak.....

Because the evap is so hard to get to, you only go there as a last resort.....you look for dye at the condensate drain, dye at the the duct work, and use a sniffer if possible.....

You say you saw nothing under the hood? Compressor shaft seal? Compressor seam? Condenser? Connections? Some low pressure lines have insulation on them......you may have to remove the insulation completely to see the dye.....