I just installed a new sink faucet. It uses Pex tubing for the supply.
The tubing and compression fittings with the nuts were already attached to the faucet.
When I made the compression connections to the shutoff valves, I had no leaks, but I am thinking that I might have over-tightened the nuts a bit.
The instructions (which I read very carefully, except for the part about how much to tighten the fittings) said to tighten one turn past finger tight, not to over-tighten.
It is very difficult to know what "finger tight" is with these old valves, because the nuts don't thread on so easily as they would on new valves.
I did tighten pretty hard, but not as hard as I could have<g>
There are no leaks, but I am just wondering whether, if the nuts were over-tightened, the connections could start to leak later on, or would they have leaked right away.
I have no intentions of un-tightening the nuts so that they are definitely not over-tightened, because I KNOW that they WILL leak after I do that.
It's under the sink, so I have access to check them once in a while if I feel the need to, but I always tend to second-guess myself after doing a job that I have not done many times before.
BTW, there is plenty of the PEX supply lines available (I had to loop it) in case I need to cut and re-do the connection at a later date.