I have a leak in my AC system. It holds a solid vacuum but by the next day I’ve lost a couple ticks on the regulator. When refilled it wont hold for longer than a week or so. I tried charging it with dye when I last charged the system but really havent seen any indicators of a leak with the glasses and UV light. Perhaps I didn’t get enough dye into the system. The system is now empty, and the compressor is unplugged. Considering the inaccessibility of the evaporator unit, does anyone have any advice on how best to begin trouble shooting the unit at this state? Should I pressurize with air plus oil/dye and look again for leaks? Perhaps purchase a listening device? I don’t want to pressurize with R12 yet because I only have so much and don’t want to waste it. If I play my cards right, i probably have enough R12 to last me the rest of the car’s life. Any advice would be greatly appreciated. When last charged, it blew COLD air. But it leaked out soon after, a week or so.