I have had a slow hot water leak in my tub for a while. I have replaced the Crane Dial Ease stems in my bathtub fixture for the second time, with no better results. The hot water still drips -- probably a quart an hour. Otherwise the faucets work great. (Note I am a different user, with a different Dial Ease problem, than 'bbbluueyes') Is it possible to screw in the stems too tight, and warp the fixture, causing a leak?

The one thing that is different about this fixture from the others just like it in my house is that there is a pipe inside the fixture, about 4 inches long, that tends to unscrew and come out with the stem. When I replace the stem, I have taped the threads at the far end of that 4-inch pipe, and reseated it, before wrenching in the stem. I have not found an explanation for the purpose of this pipe, but I am starting to think that maybe it needs to seat against the bottom of the stem, and that a little space between this pipe and the stem is the source of the leak.

Can anybody comment on my situation and my theories?