The UV dye is injected into the low side port, look for the port on larger of the 2 hoses near the strut tower on the passenger side (if you have an e30).
Freeze 12 is an R-12 alternative that works in R-12 systems, it still isn't good for the ozone but not nearly as bad. To do it yourself (not advisable) you'll still have to know someone that has a R-12 guage set and a top or side porting can opener. Adding a can of freeze 12 to your A/C system with a dye injection to find the leak is would be best for now, if your system wasn't swtiched to 134A. Most of the dye injections sets do both R-12 and 134A the dye (at least in my set) is compatible with both. Ask local garage for a UV dye injection and if they have freeze 12.
P.S. If you wipe off the inspection glass and it is dirty (brown color) from the other side you may need alot of work to get it cool again.
Last edited by Starmavin; 06-23-2006 at 10:30 PM.