Hello folks. In my bath/shower, when I flip the lever to open the drain, it pops back up a bit which leaves the drain partially closed and slows the flow of water down the drain. Any idea how to fix this? I flipped it opened then closed a bunch of times hoping that would fix it, but it didn't. It's a standard bath tub/shower, installed in the late 70s.
Thanks for any suggestions.....
Mike