A bathtub stopper that will not open or seal needs its mechanism identified before adjustment. Clean accessible debris, check the stopper or linkage using the exact drain instructions, and replace damaged model-compatible parts. A tub that still drains slowly with the stopper fully open has a different problem. Avoid forcing the drain flange or hidden overflow piping.
Identify what moves the stopper
A lift-and-turn or push-operated stopper has its control at the drain. A lever-operated assembly uses linkage associated with the overflow. Some have a visible pop-up stopper; others stop the water inside the waste assembly. Do not assume every flat cover twists off or that every overflow lever uses the same internal parts.
Find the drain's model instructions or a diagram before removing hardware. Kohler's cited bath-drain guide shows an adjustable lift rod and pop-up stopper. Its K-7142 retrofit guide covers converting specified existing assemblies to a toe-tap drain. Those are different procedures, and the retrofit is not a universal repair kit.
Clean first, then make the permitted adjustment
Remove only parts the applicable instructions identify as accessible. Hair or residue around a moving stem can interfere with travel or seating. Clean the accessible surfaces and inspect for a damaged seal, loose connection or broken mechanism. Do not bend a rod or force a seized part to make it move.
The cited Kohler pop-up instructions give a stopper-height adjustment and a separate linkage adjustment when the first adjustment cannot provide clearance. Their dimensions apply to that assembly. A toe-touch mechanism that no longer latches may need its matching operating part instead; linkage adjustment advice would not fix it.
Disturbing an overflow plate can affect a hidden seal. Kohler's retrofit instructions require access to the back of the bath and a leak inspection. If you cannot inspect that connection afterward, have the repair assessed before opening it. Removing the threaded drain flange is a separate operation covered in removing a bathtub drain.
Test movement, sealing and drainage separately
After reassembly, confirm that the stopper opens freely, closes without forcing and holds water. Then release the water and check for leaks where the repair disturbed connections. Stop testing if a leak appears below the tub.
If water remains slow with the stopper properly open, follow a bathtub that will not drain. If the ceiling below becomes wet, a bathtub leak through the ceiling helps separate waste, overflow and supply problems.