Which way to turn the roto lock air conditioning valve

[neverhit 10]

I have a pressure check manifold set and a/c was converted over to R134, but I'm not sure which way to turn the roto-lock valve when checking or adding R134. The Hayes and Chiltons, just tell you to take it to a shop. Anyone ever done this? The roto lock valves are kind of chewed up.

[bnickel 10,004]

IIRC opening the valve (turning it out) will open the lines to the valve to the compressor and the lines. it's been a while since i did mine though and i used and aftermarket replacement valve last time i redid the system and it doesn't have the closable valves like before, just connects to the compressor and hoses and has a schraeder valve. this is one area where it's definitely helpful to have the factory service manuals