Kohler San Raphael - slow leak even after new flapper

[Southbaydude]

I am getting frustrated with the slow leak in Kohler San Rafael toilet.

I have tried the following:

1. I replaced the flapper with a generic Korky and it continued to leak.
2. I then bought a Kohler original (Part# 84995) and replaced it continued to leak
3. I checked the part where the flapper sits and it is plastic and there no ridges or rough surfaces, but I smeared some plumbing grease on both mating surfaces to close any gaps that may be letting some water through..still leaks

The leak itself is very slow and I can see a small, steady ripple in the bowl and it takes about ~8min for the water level to fall below and trigger the tank refill.

I can't figure out the source of the leak..is there another inlet into the bowl (that feeds the underside of the toilet rim)? Could there be a leak in the plastic "L pipe" the connects to the flapper landing pad to the bowl?

Any clues on how to solve this? Thanks for your help!

 

[hj]

The "L" tube could be cracked. You cannot tell HOW to fix the leak, until you know WHERE it is leaking.

 

[Sponsor]

 

[Jadnashua]

Don't know if this is a one or tw0-piece toilet. On a 2-piece, there's typically a nut and a gasket that compresses the flapper seat in place, and it could be loose. Or, that valve may have a small crack in it. If that model has an overflow tube, those can sometimes end up with a crack in them, allowing water to slowly leak out.

Does the water drop to a consistent height, or does it all drain out to the top of the flapper valve opening if you shut off the incoming water? If it doesn't go all the way down, then, there's a crack at and above the height where it stops.

 

[Southbaydude]

It is a one-piece toilet. Here is a link to the spec from Kohler
http://www.us.kohler.com/webassets/kpna/catalog/pdf/en/1231831_2.pdf

That's a good clue about the height of water line when the water inlet is turned off. I will experiment with it tonite.

 

[Southbaydude]

The height clue was a good one..when the inlet supply is turned off, the water level is below the flapper and it appears to be a leaking from the plastic attachment to the bowl. I am not sure how to repair/replace this..this part is sealed to the backside of the bowl. Time to replace the toilet? This Kohler is about 10 years old.

 

[WJcandee]

Replacing the flush valve on a one-piece is usually easier than on a two-piece. It's certainly doable. I think on the San Rafael, depending on the year, it is clipped on there. Remove clips, swap valve, clip clips. Flush.

 

[Flapper]

Does it look like this?

 

[WJcandee]

Does it look like this?

I wouldn't think so. Doesn't he have the L-shaped overflow riser that connects to the front of the tank?

Like this?

 

[Jadnashua]

The thing about Kohler is, that they change things so often, it's usually really hard to pin down exactly what is there without seeing it!

 

[Southbaydude]

Yes. it looks like what @wjcandee showed. What is the part called and can I replace the whole thing?

 

[Flapper]

Yes. it looks like what @wjcandee showed. What is the part called and can I replace the whole thing?

It is a flush valve and you can replace it.

 

[Reach4]

Per the Korky site, "a specialty part is needed. Please call Kohler at 1-800-456-4537."

 

[Flapper]

I don't think there are any aftermarket parts for this; there is only the genuine Kohler part.

 

[Flapper]

This should help:
https://www.plumbingsupply.com/kohlertoiletparts-sanraphael.html

 

[Flapper]

The flush valve in the picture in post #8 is available at Home Depot
http://www.homedepot.com/p/KOHLER-F...T3j7ExTzbaPr5XpqlgsqzBoCB__w_wcB&gclsrc=aw.ds

There's also a similar one that has a round output hole.
http://www.homedepot.com/p/KOHLER-F...D5-ACl1gqFGrCkoN-arQ-hoCRzXw_wcB&gclsrc=aw.ds

 

[Southbaydude]

Thanks everyone. The part in Homedepot link matches my toilet..I'll order it and try to replace it.

 

[WJcandee]

Just to be sure, can you shoot us the K- number for the thing. There are myriad versions of a "San Rafael" over the years, and they use all sorts of different innards. I suspect we have identified the right part, but I can tell in a second with the right K- number for the toilet.

 

[Jadnashua]

IMHO, Kohler seems to have both the NIH (not invented here - therefore must be crap) attitude, and the plan of the day, which literally changes frequently. This is in comparison to most other plumbing companies that have a few solid designs, and use them for years with few changes (except for trim - the guts remain the same), and often backwards compatible. There's a reason why Kohler's parts book is HUGE and not that many places stock their parts - just too many of them.

 

[Flapper]

Well perhaps they do that on purpose so when replacements are needed, you have to buy expensive replacement parts or buy a new toilet.
That's why it's a good idea to get a toilet (or perhaps anything) that has standard and/or common parts.

 

[DiYAmateur999]

I know it’s been a few years since this thread was active but I wanted to input my recent experience as well with a new fix on the Kohler San Rafael flush valve “slow leak.” In fact it was this thread that I found on an internet search that got me close to the final fix I propose below. Sadly this issue took 4 months for me to fully resolve as I just couldn’t breakdown and pay a plumber $500...plus I’m an engineer and figured if I couldn’t solve a simple gravity leak my education wasn’t worth much. We had many other bathrooms to use in the house too.

Similarly to others on this thread, this issue plagued me continually after changing out many parts:

1st x - I changed out the flapper...no dice afterward, as water could clearly still be seen flowing into the bowl with 3 very small “trickle streams” filling the bowl slowly on both sides. I figured then maybe it was the
flapper seal.

2nd x - I cleaned/honed the circular plastic flapper seal and put a light application of Vaseline on it, thinking that might help smooth out any imperfections flapper sealing surface...no dice, it still leaked.

3rd x - I thought the small over flow tube was the culprit; perhaps it was malfunctioning and letting water drain into the flush valve top...this would add water into the bowl immediately...no dice, it wasn’t dripping or letting any water flow in during “after flush + fill state.”

4th x - Thanks to this thread I finally determined that the issue must be at the vertical square flange of the total flush valve assembly...it was the only location I hadn’t changed out and recommended by this thread to change it out. So I ordered a new flush valve kit. It got here 4 days ago...I removed the old one and it was pretty nasty...the grey gasket wasn’t looking too good but I couldn’t see an obvious place where it was leaking. I cleaned the surface and then installed the new assembly, pressing it hard against the bowl until the gray gasket compressed and the metal clips locked into the back of the bowl tabs. I thought I was finally done...but alas - NO DICE! The little streams kept pouring in.

5th x - So I took matters and creative problem solving into my own hands. I took the newly installed flush valve assembly off, totally drained the toilet reservoir (bone dry). With the gray gasket installed on the assembly, I put two layers of “RTV Gasket Maker” on both sides of the gray gasket...applied a liberal amount and formed it into a decent gasket shape. I installed the assembly by crushing it into place with uniformed force on both sides (Left + Right) of the assembly...the spring clips grabbed together quickly and like that, it was installed and crushed. I added a small amount of RTV on the top portion of the assembly just to be sure. I let the whole thing dry for 24 hours. I turned the water back on this afternoon and let the reservoir fill...and YES! Finally! It held! NO LEAKS at all anymore! I humbly submit this method as well for future “slow leak” troubleshooting.

Epilogue: I also installed a small neodymium magnet on the flapper just to be sure it carried a little extra weight to force a tighter flush seal.