The Kohler Coralais K-304 Tub & Shower Valve is a very common single handle pressure balancing shower faucet that requires a cartridge replacement to repair a drippy shower.
The Kohler Coralais shower faucet uses a Kohler Rite Temp cartridge, which stands for the anti-scald pressure balancing design. of this shower faucet that is a safety and comfort feature to prevent wild temperature fluctuations. The Kohler model # for this valve is K-304. The Kohler model # for this valve is K-304. These are very pretty shower faucets, but after 5 years or so, you will probably find that your Kohler Coralais Shower valve starts to drip.
How do I fix the leak on my Kohler Coralais Shower?
First, the Kohler Coralais 304-K shower valve consists of two main Kohler rite temp replacement parts. The mixer cap #GP77759, and the pressure balance repair kit #GP500520. Together these two parts can be purchased as a mixer pressure repair kit #GP77759 for around $100. A HUNDRED DOLLARS! you are probably screaming. Yes, unfortunately the Kohler Coralais parts are fairly complex and fairly expensive. In fact, it is often cheaper to just buy a whole new k-304 rough-in shower valve and pull the parts out of the valve and install them in your new valve!
Ok, moving on. So,
How to repair a Kohler single handle Coralais shower faucet?
First, you must turn the water off to the house.
How to remove the Kohler Coralais k-304 trim.
First remove the handle. Most trims will go on using a philips screw screwed straight into the mixer cap. Simply remove the screw cover plate, and unscrew the screw and pull the handle off. If your trim doesnt have a screw, then it probably has an allen key locking the handle on from the side. In this, case you will need a DIFFERENT MIXER CAP! There is one other type of mixer cap, that is rectangular, instead of a spline, for these specific trims.
Kohler Coralais K 304 Rite Temp Shower Valve Troubleshooting & Repair Guide
How to remove the Kohler Coralais k-304 mixing cap.
Once you have the handle trim removed, remove the two screws holding the escutcheon cover plate on and pull the small sliding cylinder off of the mixer, this is what you should see on the right. – >
Remove the two screws on either side of the metal plate holding the mixer on, and pull the mixer off. Make sure not to lose any of the screws down the drain!
How to remove the Kohler Coralais k-304 pressure balance cartridge.
Underneath the mixer cap pictured is the pressure balance cartridge. It looks like a small, black, squarish box with two ports going through it and o-rings to seal the ports. After you pull the mixer off, you should see the pressure balance cartridge, as pictured at the bottom left of this guide. Use needle-nose pliers to pull the cartridge out of the shower valve body.
Now, install the new pressure balance cartridge with the o-rings greased and in the proper position! Then install the mixer cap on top of the cartridge and install the screws, and put the trim back on.
Kohler Coralais K 304 Rite Temp Shower Valve Troubleshooting & Repair GuideYou may also have to do an adjustment on the Kohler Coralais mixer cap, so the temperature is right. The Kohler Coralais mixer cap adjusts the mixing of the hot and cold water, and if you don;t adjust it, you will usually find that the shower wont get hot enough, or if your hot water is really hot, you may have to turn it down to limit the temperature and prevent scalding. If in doubt, as always, buy the parts and hire a professional to install them.