[tirwin]

I just went through this the other day.

The FLAPS (ok, my LAPS was friendly) had about 5 different choices on the adapters. Very confusing to know which ones I needed. In the end I realized that Charlie Griffith had supplied me with the correct ones and I had briefly hid them from myself.

Some of the adapters just screw on. I think the tall silver one on the left is an example. The guick connect engages the Schrader valve in the existing R12 connection.

Other adapters have a Schrader valve that sits in between the R12 fitting and the quick connect. The quick connect pushes in the Schrader in the adapter and it, in turn, pushes in the Schrader valve in the R12 fitting.

The third type of adapter requires that you use a Schrader valve puller to remove the Schrader in the R12 fitting and it's functionality it replaced by the Schrader in the adapter.

To make sure you have it working correctly you disconnect a hose from the gauge and disconnect the R12 fitting with the adapter from the compressor. With the quick connect engaged into the Schrader blow air through hose and make sure you can feel it on the other end. If not, you have done something wrong.