View Full Version : Replace flush valve on old Kohler 3402PB?

03-10-2008, 03:46 PM
I've got an 18 year old Kohler 3402PB that will give us phantom flushes about every two hours. I did the food dye test in the bowl and noticed the bowl was turning color after 30 minutes or so, so it looked like a leak. I drained the water again, filled it slowly before it got to the level of the flapper and noticed that the dye was leaking, so I'm pretty sure the leak is coming from the flush valve seat. Does anyone have experience replacing one of the flush valves on an old Kohler?
It looks like the previous owner bought some generic flush valve and just sealed it with caulk -I attached a pic

03-10-2008, 03:49 PM
Here's the picture

03-10-2008, 08:57 PM
Ah yes the old Kohler Rialto... Better you than me!
Are you detectng my love of this toilet yet?
Problem is Koher tried about 5 different proprietary flush vaves on this lemon and never did get one that worked all that well. As you can see the aftermarket replacements are probably worse and whoever bastardized that toilet picked the worst of the worst. You could go to this link and guess which one you need from Kohler it will arrive about 3 weeks after you place your order and it may work. Maybe... Buy Lotto tickets you have a better chance there.
http://www.kohlerserviceparts.kohler.com/ServicePartsPage.aspx?DocumentID=7f70b30e8b304a498 eab9457b5cdf966&ModelID=c349f6539dd349209d19ef5b8a0c773c

Or, what I would do is take off the seat, put it out on the deck, fill the bowl with dirt and use it as a planter. As for the hole in the bathroom floor I would cover that with a brand bew Toto toilet. They do not have the parts nightmare and they flush quite a bit better than what you had there before.

03-11-2008, 10:24 AM
Much obliged for the link to Kohlers parts site. They have 5 different valves , some with what look like little flanges that you screw in and the others with a small nub on the flush valve assembly itself, with another washer that I'm guessing fits on the other side of the tank. Is it just a matter of twisting these valves into place, or is there some other funky way of getting the valve seated?
OTOH, turning this into a planter looks more and more like a viable option...

03-11-2008, 11:17 AM
You've hit upon on of the problems with Kohler stuff...they change designs on a whim, it seems, and their parts book looks more like a phone book. That is one reason why few stock parts...just too many to deal with.

master plumber mark
03-11-2008, 02:23 PM
I have gotten away with murder in the past
like I see down in that toilet tank....

I suggest you simply change out that fluid master flapper
and leave that silicone job alone....

it might actually be best to dry out the whole area and
smear another 1/2 inch of silicone on top of what is already there....
and just do the new fluid master seal...

once you tear that off you are basically opening a can
of worms.....

03-11-2008, 11:24 PM
ferguson's carries the kohler conversion flush valve kit for $37 bucks. it has three anchor bolts to anchor it into the triangle in the bottom of the tank. the flapper might still leak a little, and if it does get a plumbpak 23592 or one suggested by redwood in another thread. i'd clean all that silicone off with a razor blade and put some silicone under and over the seal before tightening the anchor bolts. be careful you don't overtighten and break the porcelain. also, you might want to immediately substitute a cheap plastic chain on the flapper, because the steel ones kink often.

03-12-2008, 01:08 AM
Thx a bunch everybody -- I'm going to order a replacement valve and give this a shot. I'll let you know later how it goes.
I'll start looking at Toto's in the mean time just in case this doesn't work out..........