[ddsmith]

The one on two guys garage was made by Castrol. I used the one made by Interdynamics. It does work but it is sort of hard to get things just right without using gages. Even though most of my R-12 was gone I used a venturi vacuum device (hook compressed air to it and it draws a vacuum down to around 29", I got mine from harbor freight for $12) to draw the system into a deep vacuum to remove the remaining R-12 and potentially any moisture in the system. Then I broke the vacuum using the oil supplied in the kit(hooked the oil can to the fitting) without the compressor running. Then chased it with R-134 until the vacuum was gone. Then I started the compressor and charge utilizing the compressor suction to draw the 134 into the system.