How I repaired flush gasket on Kohler Rialto 3402PB

[Desert Lion]

I have a Kohler Rialto 3402PB toilet, http://www.designtool.kohler.com/us/detail.jsp?item=9548202 This is Kohler's photo:

This was installed new when I had my house remodeled in 1986. It's in the guest bathroom so it didn't get a lot of use. The filler began running for a few seconds every few minutes.

I had long ago replaced the original ball float with a Fluidmaster filler. I neither realized nor noticed that this greatly reduced the utility of the rim flush feature, but oh well. That replacement was a long time ago, so I figured the filler was the problem. But replacing that didn't help. I next replaced the already very old flapper. That didn't help either.

I did some reading and found this site. I went back and looked and realize the foam rubber gasket under the flush valve assembly looked extremely worn.

I found the Kohler siphon vortex toilets repair manual online:
https://www.us.kohler.com/onlinecatalog/pdf/106423_9.pdf

I called the Kohler information line 1-800-456-4537. The lady seemed to have access to everything about this model toilet. She said there were several different flush mechanisms used for this model toilet. She walked me through removing the flapper and sticking my fingers under the hole rim to feel for things attaching the flush mechanism to the ceramic tank.

I have one with a triangular hole in the ceramic tank, and three outward pointing triangular plastic brackets sticking out from the base of the flush mechanism housing. The flush gasket stretches over these brackets and fits onto a short cylindric portion of the flush mechanism. To attach the mechanism to the tank bottom, line up the three flanges with the triangle angles, push down to compress the gasket, and turn the mechanism so the brackets move from the angles to the sides of the hole. This compresses the gasket between the plastic flush mechanism and the ceramic tank bottom, making the seal.

She said they don't make that gasket any more, and they don't make that flush valve mechanism. She suggested I buy a Kohler 83095 flush valve kit, around $27 plus shipping.

I went to Home Depot online and searched on "Kohler Rialto flush valve gasket." I found this generic gasket, intended to use between the tank and bowl of a 2-piece toilet:
https://www.homedepot.com/p/Everbilt-Extra-Thick-Beveled-Sponge-Rubber-Gasket-40477X/205172299

I went to the local Home Depot with my removed flush mechanism in hand. The plumbing assistant knew a lot about plumbing, which was nice. He was not complimentary about Kohler because he said they don't carry parts for very long. He hadn't heard of using this particular gasket to fix a one-piece flush valve, but said I should try it, since it's less than $5.

I took it home. I cleaned the flush mechanism and ceramic tank of old rubber gasket remnants with a plastic pot scrubber. I put this gasket over the flush mechanism housing, screwed it back into the hole, and filled the tank. We're at 3 hours now and no leaking.

 

[WJcandee]

Thanks for an interesting post.

Generally, the folks at HD appear to know something about plumbing, but in fact do not. The amount of bad advice coming out of there that we have to later correct on here is staggering.

That's why you will sometimes see us suggesting that a forum participant go pick up such-and-such at HD, but admonish them, "Regardless of what the Apron at HD tells you, do not under any circumstances pay any attention to it. Just get this part and bring it home and install it the way we said to." That usually keeps our participants out of trouble and yields the result we hope for.

 

[Sponsor]

 

[KIlgoreTrout53]

Thank you !!!

I have the same model, similar vintage. Leaking and water wastage was driving us crazy. After trying multiple fill valves, I realized that part of my problem was on the flush valve side of the unit. After reading the above, I pulled out the old gasket and matched it up with an Everbilt gasket at HD for about $3. They are roughly the same size. The valve assembly twists in and out of the triangular hole fairly easily. I also replaced the flapper with a Korky part. If the top of the original plastic valve unit is smooth and free from burrs or damage, there's not much reason to replace the whole unit. After reading some of the negative experiences folks had with the "updated" kits, I decided to approach this one piece at a time.

Important note - install the gasket FLAT SIDE DOWN. This is the way the original was oriented, but opposite to what the package instructions display. You can also get an OEM gasket part #GP83888 from various suppliers, it's about $6. That will be my next step if the Everbilt leaks. So far, so good.