A/C refrigerant leak detection ?
 

My 1983 300SD leaked out the refrigerant ( to the point where the compressor would not turn on) after abount 3 weeks after a compressor replacement - using Freeze 12 . I need to check for leaks before I go any further . I was thinking about using some of that R134/dye in can from Autozone etc because I need a dye and a way to inject the dye into the sysem . just for leak detection since I will have to make repairs a evacuate the system anyway . Will this stuff hurt anything ? Ohter other recommedations are appreciated . - Thanks

No the dye is made just for that and will not harm anything. Freeze 12 is mostly R134 as an ingredient.