Modern bathtub drains, controlled by a lever on the overflow plate, operate in large part from a position of concealment. Hidden in the bathtub overflow tube is a so-called lift linkage that, rising or falling in response to the control lever, opens or closes the drain in one of two ways. A pop-up drain utilizes a metal stopper at the tub outlet, while a trip-level drain regulates the outflow of water with a plunger at the intersection of the overflow tube at the drain.
A common problem of bathtub drains is clogging caused by the accumulation of hair on the trip-lever drain plunger or on the spring at the end of a pop-up drain lift linkage. To remove the hair, the lift linkage must be removed from the overflow tube.
This is done by unscrewing the overflow plate and pulling on it. The same procedure is sometimes necessary in order to adjust the length of the lift linkage; improper adjustment--perhaps caused by faulty installation, perhaps by wear and tear--can result in a leaky drain or one that fails to open fully.
The various conduits of the drain--the overflow tube, outlet pipe and trap--are less likely to suffer problems than those of lavatories or sinks.
They are usually made of heavier pipe with sturdy cast-brass fittings that strongly resist corrosion. And their hidden position protects them from accidental knocks.If your pop-up drain leaks, the O-ring below the metal stopper may be worn. Open the drain and pull out the stopper and the rocker linkage. Clean these parts of accumulated hair. Slip on a new O-ring, then replace the stopper, working it sideways or back and forth until it clears the bend in the pipe. Make sure that the bottom of the curve in the linkage faces down. It's that simple!
Adjusting Bathtub Drains