I have a pvc water supply line attached to another plastic line via a male/ female threaded adapter. There is a tiny leak from the connection, most likely because I failed to use enough teflon tape. How can I stop this leak without taking everything apart, as I have glued all the other joints together with pvc adhesive? Would it be possible to use a small amount of glue on that connection as well, or will it destroy the teflon tape underneath. Thank you

Hayden... any chance of posting a picture of this? Let me know.

Sounds like you have a compression fit. If this is a compression fit then you do not want to use teflon tape or pipe dope for the connections.

Remove the teflon tape. Try to re-install the plastic line... hand-tight plus one full-turn and then turn the water back on. If that fails, purchase a new toilet supply and then WITHOUT TEFLON install the connector hand-tight plus one full-turn and then turn water on... see if that does it. If that fails tighten a 1/2 turn at a time and keep testing. If that fails then the shutoff itself may be the issue and will need to be replaced.

Let me know what you think...

MARK

PVC is easy to fix. Cut the pipe, remove leaking fittings, replace with new ones, glue back together. You will be done in few minutes. Also, see if you can avoid the Male/Female threaded connection and replace it with piece of pipe.