The kit at Wal Mart contains goggles and light, not dye and light. UV dye for r134 systems is also available at Wal Mart. R12 UV dye is another matter. There is a kit available at ackits or acsource that has dye and an injector that you can use for R12 or R134 systems. That would be your best bet on an R12 system.

They also have an EXCELLENT book about auto a/c it is the Mastercool manual. I would strongly recommend that you get and study the manual before embaking on this task.

Not understanding these systems can not only result in damage to the system, but also personal injury.

Good luck,