GP500520 Pressure Balancing Unit Cartridge Replacement, Compatible With Kohler Shower Cartridge, Kohler Shower Valve, Rite-Temp Bath and Shower 1/2" Single Handle valves

Works great. No leaks. Good price.

Genuine part delivered fastI purchased this unit because my shower temperature became uncontrollable. It would either be very hot or very cold, but never the right mix. So, I searched the Kohler online to find the solution, it suggested that I should change the cartridge, then I ordered it on line. Surprisingly, it was delivered the very next day. Installation was easy even for a novice just 4 steps, there was still videos online. I simply replaced the old part and rings with matching new ones. Two wide black rings for the outside and the two small black rings for the inside. For now, it seems to have solved the temperature control problem, but how long this lasts the time will tell us. We are so happy our shower just like the new again.

fixed the water adjustment problem

With a little knowledge of plumbing anyone can replace this cartridge. Shipping was fast and the price was right. However, the gaskets that were included did not fit the unit. I had to use the o rings from the old unit on the new one. So far, there are no leaks.

After installing, the valve leaked. Turns out it had nothing to do with the replacement cartridge. After much on line searching, I found the valve housing was corroded where the main o-ring seals. There was scaling and green corrosion on the brass housing causing a rough surface and a leak at the o-ring seal. I used a light acid solution to remove most of the corrosion and scale then I used 800, 1000, 3000, 5000, 7000 and 10,000 grit wet paper to polish the surface. Added a little silicon grease to the o-ring and valve surface, reassembled and the leak was gone. The unit functions perfectly. I would not be surprised if some of the "leaking" problems reported by others were not due to this issue. Also, I disassembled the failed pressure cartridge out of curiosity and found the internal pressure diaphragm was completely rotted away causing random mixing and unstable/unpredictable temperatures. This failure also caused the nearby bathroom sink to have hot water coming from the cold faucet! That was a very bizarre and confusing symptom. Hope this helps someone.