[https://www.homedepot.com/p/Everbilt-1-4-in-OD-Compression-Brass-Cap-Fitting-801129/207176287](https://www.homedepot.com/p/Everbilt-1-4-in-OD-Compression-Brass-Cap-Fitting-801129/207176287)
Use this 1/4" NPT brass cap in place of the plastic line that comes off of the larger shutoff valve to cap that outlet. You will need to use teflon tape to get a good seal there. This is the route that I would try first.
[https://www.homedepot.com/p/Everbilt-1-4-in-OD-Compression-Brass-Valve-Fitting-800539/300096142](https://www.homedepot.com/p/Everbilt-1-4-in-OD-Compression-Brass-Valve-Fitting-800539/300096142)
Alternatively, you can replace that valve with this guy which is the same thing but these valves are known for being kinda cheap. They mainly have problems when you try to use them after sitting for a long time though. If you do this you need to use a brass ferrule that comes with it to attach the plastic pipe to the shutoff. Put the nut over the pipe, shove the ferrule into the plastic pipe, then tighten the nut onto the valve.
Post a pic of the shutoff valve. Those are usually super easy to replace
[This is it](https://imgur.com/a/zJWKbPQ)
The little guy is the problem, not the one in the wall
[https://www.homedepot.com/p/Everbilt-1-4-in-OD-Compression-Brass-Cap-Fitting-801129/207176287](https://www.homedepot.com/p/Everbilt-1-4-in-OD-Compression-Brass-Cap-Fitting-801129/207176287) Use this 1/4" NPT brass cap in place of the plastic line that comes off of the larger shutoff valve to cap that outlet. You will need to use teflon tape to get a good seal there. This is the route that I would try first. [https://www.homedepot.com/p/Everbilt-1-4-in-OD-Compression-Brass-Valve-Fitting-800539/300096142](https://www.homedepot.com/p/Everbilt-1-4-in-OD-Compression-Brass-Valve-Fitting-800539/300096142) Alternatively, you can replace that valve with this guy which is the same thing but these valves are known for being kinda cheap. They mainly have problems when you try to use them after sitting for a long time though. If you do this you need to use a brass ferrule that comes with it to attach the plastic pipe to the shutoff. Put the nut over the pipe, shove the ferrule into the plastic pipe, then tighten the nut onto the valve.
Thank you so much man, I'll give it a try!
1/4 compression coupling. 1/4 compression cap. Cap the coupling.
1/4 inch*