The seal at the stem is loose. Depending on what kind it is you may just have to tighten the nut to compress the packing. If it does not have a nut then the seal may be internal and the stem is bad. It should have nothing do with any leak inside the wall.
: We were getting a steady drip from the shower-head.
: Even when twisting both faucets hard-shut, there was
: a constant drip.
: The house is about 30 years old, with
: original equipment in the shower.
: I went to the hardware store, and described problem.
: The guy in the store suggested replacing cold & hot
: faucet stems, and seats. He thought my old seats
: were scarred, causing incomplete water shut off.
: I bought new stems, handles,
: seats, stem extraction tool, and seat wrench. I also
: bought a new shower arm and shower head and thread
: tape. I went home, extracted old gear, and installed
: new gear.
: I no longer have water drips when faucets are shut,
: and I think he was right, that replacing the seats
: fixed that problem.
: But, now I am getting leaks both at shower head
: and at faucets whenever I open either hot or cold tap.
: Here are the symptoms:
: When I remove the shower head, so
: that water runs freely out of shower arm, I get some
: slow dripping coming out of hot water faucet handle.
: When I remove that handle, the water is coming
: out of the stem.
: When I then replace the shower head (it's a fancy
: new massage-head unit), having carefully wrapped
: teflon tape around the arm threads first, I
: get some water dripping out of that joint. However,
: I get a lot (!) of water coming out of the hot
: water faucet stem, and also some water dripping
: out of cold water stem. Apparently the increased
: water pressure in the system due to water being
: forced out of shower head is exposing the leaking
: more obviously.
: I'm thinking maybe the seal between shower arm
: and the water main behind the tiles isn't good, though
: I did carefully teflon-tape that threading too, and
: hand tightened arm as far as I could.
: I'm at a loss. New seats, new washers, new stems,
: new handles, new shower head, new shower arm,
: new teflon tape, but drip drip drip. HELP!!