A shutoff valve connects to copper plumbing pipes in one of two ways: Compression fitting; Sweat fitting. Identify the connection type used in your home by referring to the photos below. If you have ...

Tighten the packing nut on the toilet shutoff valve one-eighth turn clockwise to try to seal a leak around the nut. Pro tip: Wrap cloth or masking tape on the plier’s jaws to protect the nut’s finish.