Sounds like you may have a leak in the spout piping. When you install the
spout there is then enough backpressure to force the water out the leaking
spot. Without the spout, then isn't enough backpressure to force the leak.

Do you have any access to the back side of the tub. Like in a closet or
something. You would need to cut an opening. If its in a closet, you can
just make a nice panel to cover the cut out.

Darrell


"CJ" wrote in message
oups.com...
If I connect the tub spout to the copper piping and run the water
completely thru the spout; water drips to the underneath ceiling. If I
disconnect the tub spout so only the copper piping shows, and then run
the water completely thru the spout; no water drips from underneath.

Does anyone know what this could be?