My bathtub has been dripping for few months. Yesterday, I finally worked up a nerve to tackle the project, but I am quite lost.
I thought I would just need to replace what I thought were Kohler Cartridge and/or Pressure Balancing Valve.
I think I have K-15877-K-NA Coralais Shower Valve which can be found at https://www.kohler.com/en/support/he...h-shower-valve
This is what I took out:

What I took out.
But I cannot identify what Kohler Pressure Balancing Unit I have. Here is the picture.

My Pressure Balancing Unit?
I am trying to take it out to put a new one, but I cannot get it out. Can I just replace the cartridge and hope it will stop the drip? Also, which Kohler Valve Trim to put in since all new ones require "Rite-Temp Valve" system. Once again, I am quite lost. Can someone help? Thanks.

 

Have you contacted Kohler? They can be helpful and might even send you the needed parts for free.

 

No, I have not. I will give it a try. Thanks!

 

I just got a generic replay back.
Thank you for contacting Kohler. I am very sorry to hear that you are experiencing this issue. The parts that Kohler would recommend replacing would be the balancing spool, as well as the mixer cap. I have attached both part #’s, these items can be purchased directly online, or even at times from the local home improvement stores. I have provided a link to your genuine part dealers.
KOHLER Where to Buy 
https://www.kohler.com/en/locations?q=48198

Service parts recommended.
GP800820 Pressure balancing cartridge.
GP71969 Valve Mixer Kit

No help with how I can get the pressure balancing cartridge out. At his point, I think I need to get it out. I do not want to mess with putting in a new valve system. It may be too much for me.

 

It sounds like you Emailed instead of calling on the phone and asking. On the phone you can ask and get an answer to your questions. With Email you can sometimes get a canned response and if you have multiple questions not all of them get answered.

I'm not understanding why removing the balancing unit is difficult. Check to see if you've already removed a part that looks like this.

 

These two are only ones I removed.

This was on top. I think it is the Valve Mixer Kit.

This was on the bottom which I am assuming is the pressure balancing cartridge. The house was built in 1991, and I moved in 2 years ago. Who knows what the previous owner did.
I will try calling them tomorrow when I have time to make a call. I am waiting for them to respond to my inquiry to their first response.

 

Maybe this will help:

 

I got that, but I do not have GP800820.
I have this instead and I cannot get it out. That is my problem.

Maybe I am not being clear, and I apologize for that.

 

You can start by spraying the perimeter with penetrating oil. Give it plenty of time to soak in and repeat.

You can try sticking a dowel, piece of pipe, big screwdriver or anything into one of the holes. Then hold it crooked so it wedges in the hole and try wiggling and pulling. Move back and forth between the holes trying to loosen it.

You can also measure the size of the big holes. Get a expanding masonry (Hilti) anchor that just fits into the hole. You can fine tune the size by wrapping it with tape to make it bigger. Then put a scrap of steel or strong board across the face of the faucet with a hole in the middle. Run a anchor bolt through the hole into the expanding anchor that is stuck the hole. As you tighten the bolt the expanding anchor grabs the inside of the hole and tightening it further will pull it out (hopefully).

 

Thanks for everyone's help. I just cannot get the pressure balancing cartridge out. Talking to Kohler has not helped. I don't think they know what I have. I think I have to change mine to Rite-Temp valve system from Kohler which involves cutting my drywall, etc. I guess I have no other choice at this point. Should I stick with Kohler or switch to other well known brands like Moen or Delta? Any suggestion? Thanks.