I removed the old stem and replaced it with a new one, but water won't completely shut off. What do I need to do?:confused: [email protected]

If this is a stem with a rubber washer held in place by a screw there is a posibility that the seat that the washer closes is pitted and will need to be changed. Take the stem out again and use a flashlight to look back into the hole where the stem goes. Where the washer seats should be very smooth. In the center there should be a wrench hole, either sguare of hex. Unscrew it the same you would a screw, go to a good store and buy a new one. Same size and same threads. If this in not the kind of stem you have then describe it to us.