This seems so absurd, it must be a bad joke. After several months of demo and construction, the countertops were finally put in this weekend. As I went about hooking up the faucets to the supply lines, I found that 3 of the shutoff valves were leaking slightly once I turned them on. THREE!!! One is a (old) supply shutoff valve right underneath the bathroom sink, one is a (old) gate valve to the shower, and one is a (new) ball valve to the kitchen sink. All of them are on cold water lines.
All of them had been shutoff since before demo, but had not leaked at all during that time (or prior to). They are leaking through the stem, not at the in/out connections. I guess I can try replacing the o-ring/washer in the gate and shutoff valves, although of course now they're really incovenient to get to. I'm really pissed about the ball valve, though. I've been using them specifically because I'm sick of leaking gate valves.
Am I missing something? Is there a miracle fix that will save me the pain and agony of wedging myself inside the base cabinets to replace these?