Can I overturn (clockwise) the cold water shut off valve under the kitchen sink and spring a leak at the knob ?

Question

I am changing out the kitchen sink faucet. / The threading on the shut-off valves have no threading. The main shut off valve (to the house also has no threading) ; however when turning the cold water valve clockwise with pliers, it will only turn so far, with light pressure, and the cold water does not stop flowing, in the sink. Can I spring a leak at the shut off valve, if I use too much pressure, using pliers, to force the valve futher clockwise to shut off the cold water. ( The hot water valve turns off/on with the use of pliers, under the sink)

Answer 1

Yes, you certainly can. Too much force and you will break it and have a real mess. You need to replace it, first shutting off that main, and may as well do both stops under the sink, preferably with quarter-turn ball valves. If the valve is soldered on copper pipe, fastest to just cut it off right behind the valve - if there's enough copper to work with. If it's super-short already, better to unsolder it, add a coupling and a stub of fresh copper, then go from there. Nice to have like 6" of copper in the cabinet. This is why.

Plan B: At Ace, we now sell a "repair valve" 'stop, with a female 3/8" compression fitting on the inlet side. If that's the size of your supply line from the valve, it would get it done. I don't like the idea of putting a new valve on a bad valve, but whatever.

Answer 2

if you have well water flip the breaker for the well pump and drain of the water pressure the you can change all shutoffs. however if you have city water talk to the water authority they may have a shutoff outside your house which can allow you to change the shutoffs' however if none of those are available use a shark bite fitting with a short piece of pipe and a shutoff valve already connected cut your main supply line and quickly shove the shark bite fitting on to the line with the shutoff open to allow the pressure thru then simply turn off shut off valve then change your other valves then reconnect water lines and turn shutoff on

Answer 3

First identify the type of valve you are dealing with.

Second - don't use pliers. They are designed to work with hand pressure or a service valve with a flat screwdriver. They are either 1/4 turn or tap type needing many turns, but none of them need to be forced.

If you don't know how to turn the water off - STOP! and get someone who does. Better - buy a diy book on the subject.

Answer 4

yes you can but it comes from the valve seat not the knob. you need to make sure the main can be turned off before you deal with the shutoff under the sink or you will have a mess.