More than likely, it's either a bad valve "core" or a bad-seated valve "stem". Flaking chrome is not going to cause a leak in the wheel, as chrome is only a plating over the original metal surface. In the rare event you had a piece of flaked chrome or other debris caught inbetween the tire bead and wheel lip, then that would cause a slow leak as well. A "submerged water dunk tank" test will find it.
Take your VX over to your local:
LES SCHWAB TIRE CENTER
2602 GEER ROAD
TURLOCK, CA 95382
TEL: (209) 634-3115
Les Schwab Tire has top-notch tire service.