Last night I did more investigation in my garage. I rand my hand under the valve and it came out smelling like gas. Something an't right. I took a piece of paper towel and bloted the vent and found a small damp spot. I put a vacume pump, that I use to flush the brake lines, on the #6 hose and watched the vent. Could not make it leak and the vacume held. This morning at 5:30 I ran my hand back under the valve and it was damp again. Not dripping, just damp. Something is leaking and justifies a tear down.
Sounds like the vac side of the diaphragm is okay and the fuel one is bad/worn (there are two, linked together).
No amount of fuel leakage is acceptable.
Replace the cover-set (including the cover!)