(a) tightened connection holding upper tubing with channel-lock pliers, still leaking
(b) tightened it more, still leaks
(c) tried again, it won't turn any further. ............. &^*%$THING STILL LEAKS !! Gurrrr
I'm thinking that the leak is coming from mating surface of faucet tubing, or cracked tubing up above the connector. Does it make any sense to unscrew the connection and add silicone grease, and try to tighten the connection, or start fresh, and replace the faucet? I have a faucet that's been sitting in the garage for a few years, came together with a sink.
Installed the sink, but didn't use the faucet on that job, so cost to me is zero, as I see it.
Because I want these turkeys (Pfister) to make good.
When I replace this faucet (doing kitchen over by end of this year) I'll put in a Delta or Peerless with the stainless ball and replaceable seats/washers & springs. I've found them to be longest lasting and easiest to service faucets I've owned. JMHO