I'm rebuilding my C-6 using a Bad Shoe/Broader/ factory shop manual method.
I'm to the point where I'm doing the air checks and everything is good except the servo, which leaks and does not move at all when I hit it with air.
I had the "newer" style one piece servo in there first and then I rebuilt my old style servo and the results are the same. The air seems to be blowing out of the hole the servo shaft rides in.
You may be applying air to the release chamber.