Fixing a leak under the kitchen sink?

Question

i had a hard time tightening the hexagonal nut (because it was stiff) underneath the sink to stop the hot water from leaking behind the hot water valve. but a few hours later when running the hot water the water started leaking under the sink again. i think its not tightened enough.

should i put wd 40 on the hexagonal nut to loosen it up so it can be tightened further?

Answer 1

Make sure the nut is on the threads and not stripping them.

Use a pipewrench and you should have no problem.

Answer 2

turn off hot water at water heater, turn on hot water on KS faucet till it stopps running. unscrew compession nut behind valve ( no wd40 needed) you will see a compression sleeveunder nut slide nut back enough to put some pipe thread coumpond around sleeve. put back together and test. If still leak, cut pipe behind sleeve and replace