134A has different connections then R12 did. If you have standard 1/4" flare fittings you have R12. If your connections larger and look like a quick connect fitting you have 134A. As for the Schrader valve leaking when you take the cap off I wouldn't worry about. It will get changed if you ever have the system service.
1999 35 ft. Dolphin 5350, F53, Banks System, 5 Stars Tune, Air Lift Air Bags, Koni Shocks, Blue OX TruCenter, TigerTrak track bars F&R, Roadmaster 1-3/4" rear auxiliary sway bar, 2004 F450 Lariat Pickup 6.0 Diesel Crew Cab DRW, 4X4, GVWR 15,000, Front GAWR 6,000, Rear GAWR 11,000, GCWR 26,000, 1994 36ft Avion 5er, GVWR 13,700, 2,740 Pin Weight.