My mother's house has a shower that has a perpetual drip; the valve is likely original to the house (probably ~1970) and I expected it to be a pressure-balancing valve with a cartridge and replacable o-rings and gaskets that were likely deteriorating.

The valve operates by pulling out to allow the water to flow and pushing in to shut off the water. Twisting it controls the temperature. I've removed the cover and didn't find what I expected--so I took these photos:

  • The cover plate has been removed, the cover does not hold the handle in place (the handle could be removed with the cover on).

Cover Plate Removed

  • The valve with the handle assembly removed


  • Another view of the valve


  • The handle assembly

Handle assembly

I expected the black plastic to be a removable cartridge, but it seems to be firmly in place (I've just tried twisting and pulling by hand--not much force, but it doesn't budge or wiggle). The handle screws pass through the black plastic and into the body behind it.

So, the main question: Does this unit appear to be serviceable--if so how can I get deeper to identify the cause of the drip--how would I pull the black plastic without damaging it? Or is it just time to get into the wall from behind and replace the whole valve?

...and yes, it'll get caulked during reassambly


2 Answers 2


Figured it out. The black plastic piece was a removable cartridge, I rocked it side to side and it began to give a bit--after that I lightly threaded oversized bolts into the normal bolt holes and was able to use them to rock and pull it out. I found that it was a three-piece cartridge; the outer portion contains the water inlets and a rubber gasket on the back, and the center piece is flexible rubber. All pieces had a large amount of buildup on them and the rubber had become very stiff--either the buildup or the stiffened rubber were likely preventing the valve from fully closing.

I found a replacement kit (Kohler Centura kit #42178) at Home Depot; the rubber was much softer and the result is no more drip.

Here's a couple more photos:

  • The cartridge after removing it, showing the backside covered with a thin gasket and the water inlets; and the long central piece which is rubber. Cartridge after being removed

  • The valve body with the cartridge removed enter image description here


Glad you found your answer.

I've also had slow leaks (drips) like you experienced due to (1) solder spatter inside the valve that prevented a good seal on the rubber, and (2) plumber soldering the pipe with the cartridge in place which hardened the rubber so it didn't seal well.

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