I tried to shut off the water under my bathroom sink (turned clockwise until it stopped). However, after doing this the water still comes on when I turn on the faucet. This is true for both hot/cold. I then turned the valve all the way counterclockwise, and the water still comes out. The problem is now that each time I turned the valve the water pressure changed, and is now just a trickle - but still definitely "on". Any advice out there?

Sounds like the washer in this stop is now shoot and coming apart. Shut off your main and then back off the nut immediately below the handle and then unscrew the stem from the valve. Do you see a deteriorated washer or a small cartridge like valve?

Hi Camphoto:

First, remove the AERATOR (see pic.) at the end of the spout (loosens clockwise)... clean it and then run water without it in place. Any improvement? If so, great! Replace the aerator for now but you have issue with the shutoff washers (dryed out and cracked) and will need to replace the washers or shutoffs to both the hot and cold pipes. All will depend on the type of shutoff you have...

1st) compression
2nd and 3rd) solder types
4) threaded... see pictures below (in order)

For compression type shutoff you would probably be best to purchase a new pair of 5/8" O.D. compression shutoffs and install them.

For solder types you may be able to purchase a copycat shutoff and just replace the washer. Here, the last 10 years or so washers on these shutoff types are not held on by screws but instead they are held onto the shutoff stem by snapping the washer over an enlarged stub. Point is that you cannot find these washers in a common washer kit and the manufacturers of these shutoffs do not sell replacement washers readily.. ;) Better to buy copycat and either replace the shutoff itself or loosen the packing nut (behind the handle) and remove the stem assembly to reveal the washer and SWAP those onto the old shutoffs

For the threaded types you may be able to find a washer that will screw onto the stem assembly in a common washer kit or may be best to unthread the old shutoff and replace with a new threaded shutoff. This may also be something left to an experienced plumber as sometimes threaded piping can lead to other issues that get expensive if pipes get mishandled... ;)

Anyway... let me know what you have here...

HEY BOB...was writing (as you can see...:rolleyes:) as you were.

MARK

My valve looks like all of these. I'll try shutting off the main and removing the valves. Hopefully Lowe's will have what I need!