Kohler 1-pc Rialto flapper leaks

Discussion in 'Toilet Forum discussions' started by Muggins, Oct 20, 2006.

  1. Muggins

    Muggins Plumber

    Messages:
    3
    Location:
    San Jose, CA
    My Kohler one piece toilet has been working fine for
    about 3 years, now, but recently, the simple rubber
    flapper has been leaking at various rates after I flush.
    Sometimes, it makes a good seal, but usually it slowly leaks.

    So, I replaced the flapper but it still leaks sometimes,
    not always. I've fiddled with the adjustment. I'm a
    plumber (construction plumber, not a repair plumber)
    and I'm supposed to know how to fix this thing, and it's
    kinda embarrassing. Is there anybody ever had a similar
    problem?

    [​IMG]

    The drain hole to the bowl that the flapper seats on is
    2 9/16" in diameter. The flapper measures 2 3/4" in diameter.
    Not much overlap is there? Maybe an after market flapper
    might work better, or what?
    Last edited by a moderator: Sep 15, 2009
  2. Verdeboy

    Verdeboy In the Trades

    Messages:
    2,051
    I researched this a bit, and apparently there is some sort of design flaw here. People have had to try different brands of flappers before they found one that works. Kohler has even agreed to ship entire new flush valve assembly to some.
  3. Muggins

    Muggins Plumber

    Messages:
    3
    Location:
    San Jose, CA
    That sounds about right, Verdeboy

    Thanks for that quick response, Verdeboy.

    A rubber flap seems to be such an uncomplicated and
    simple valve design, it's a wonder that Kohler could design
    something that didn't function very well, but they managed
    to do so. The problem is so simple. The diameter of the
    rubber flapper is an 1/4th of an inch too small.

    I tried calling Kohler, but they couldn't help me because I
    didn't have the serial number of the toilet. I got the impression
    they didn't want to bother with it. "Can't help ya." was the
    last thing I heard from them.

    I'd be interested to find out what flappers work better than the
    Kohler replacement flapper.
  4. Muggins

    Muggins Plumber

    Messages:
    3
    Location:
    San Jose, CA
    I found something on the flapper

    At this site, they talk about the Kohler flapper
    problem.

    The recommendation is to use Korky flappers,
    maybe a #58.
    Last edited by a moderator: Sep 15, 2009
  5. dx

    dx General Contractor

    Messages:
    156
    Location:
    Michigan
    Reviving this old thread because I have a client with same problem. Flapper leaks, new flapper leaks just the same.

    This is the system with the rectangular standpipe. The flapper has a rectangular rubber "ring" that fits around the standpipe.

    The problem is the chain pulls on the flapper sideways and the flapper comes back down not so straight. Works about 80% of the time, the other times you have to jiggle the lever.

    I talked to Kohler tech and they appear to be aware of a design issue. They offered to send me a free "longer" actuating lever. Just got it in the mail. It's no different than the one already in the toilet.

    Has anyone found a fix for this? Does anyone make a kit for replacing the entire guts of the toilet with something that works?

    Thanks
  6. Verdeboy

    Verdeboy In the Trades

    Messages:
    2,051
    Most times, you have to cut off that rectangular ring with a scissors to get it to seat properly. Just hook the two remaining holes on the sides of the flapper over the hooks of the flush valve.
  7. dx

    dx General Contractor

    Messages:
    156
    Location:
    Michigan
    Eric,

    You are talking about a different system. The one I am talking about has no hooks, holes or any other mounting provisions.

    See picture. The back part of the rectangle (thinner) snaps into a groove on the back of the rectangular tube.

    Attached Files:

    Last edited by a moderator: Jan 23, 2007
  8. Verdeboy

    Verdeboy In the Trades

    Messages:
    2,051
    My mistake. Maybe you can replace the flush valve with a more universal one (that has the little hooks) and get a standard Korky flapper.

    But before I tried that, I'd try adjusting the chain on the flapper you already have. You might need to leave a little more slack. Also, If the lever has a metal rod that is attached to the flapper, maybe you can bend it a bit to lift up the flapper straighter, or you can replace that lever with one that you can bend in such a way.
    Last edited: Jan 21, 2007
  9. dx

    dx General Contractor

    Messages:
    156
    Location:
    Michigan
    Thanks Eric!

    I already fiddled with the chain and all that. There is no room in the tank to even make a custom lever that could pull straight up on the flapper.

    Took your suggestion and looked closely at the Kohler site. Lo and behold, their current parts diagram for the Rialto K3386 shows a standard flapper style with eyes and corresponding hooks on the rectangular tube.

    Somewhere along the line they must have changed it when they realized the old style isn't working! All I have to do is update to the current Rialto flush valve.

    Thanks again
    DX
  10. gjhaag

    gjhaag New Member

    Messages:
    1
    Location:
    Louisiana
    Same problem.....fixed for me

    Guys I have the same frustrating problem witht the Kohler hinge flap. Whenever you flushed the flapper pulled to the left and wasn't completed seated. I bought a couple of different flappers (thinking there was a defect) and then started to research the problem a bit. However I figured out that I didn't have the flapper snapped into the ridged place holders in the back. You have to pull forward very hard and make sure that the rubber hinge is seated in the ridge. Once I did that, the flapper no longer pulled to the left when flushed. There are different heights of ridges. I snapped mine at the third ridge from the bottom. Hope this helps.
  11. grazzy

    grazzy New Member

    Messages:
    57
    Location:
    Virginia
    i just fixed a stubborn rialto with the rectangular valve by taking a couple of rubber faucet washers and placing them on the hooks between the eyes on either side of the flapper and the flush valve tube. this keeps the flapper from having so much play when it comes back down. the best flapper is one i got at lowe's with the styrofoam on the under side. also had much better success after switching to a plastic chain. the metal one was always kinking.
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,230
    Location:
    Cave Creek, Arizona
    rialto

    You are also referring to a different Rialto flapper. Kohler has a tendency to make revisions, creating many different parts for the same model fixture.
  13. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Ripping that sucker out and putting in a Toto Drake would be a great fix!

    It would give them a better flushing toilet too!
  14. grazzy

    grazzy New Member

    Messages:
    57
    Location:
    Virginia
    you are correct, but i believe the one they are now selling is the rectangular valve with the hooks, and it has a problem similar to the one described in this thread with the flapper not seating correctly all the time. the fix for it was pretty simple. dx said he's about to try that valve and it may not completely resolve his issue without the modification i described.

    [​IMG]
    Last edited by a moderator: Sep 15, 2009
  15. polishsausag

    polishsausag New Member

    Messages:
    1
    Location:
    harpers ferry, wv
    Leaky Kohler sucks

    Thank you for the great info in this forum. I figured it was a design issue with the hinged flapper and spent the earlier part of today looking for an appropriate replacement with some re-enforcement on the sides to prevent it from traveling. I was just about to send Kohler threats for new guts when I discovered (upon finding my model number, mine is K-3384-2 which is located imprinted in the back of the tank) that they have phased out the korky style cheap rubber flapper with a better one. 84995
    Replaced by GP84995 http://www.kohlerserviceparts.kohle...ervicePartID=7742957e75934809abf3b23a91dc463a

    This new one seems to have a solid plastic stick that snaps into the Hinge slot, and sides with more rubber and grooves to keep the flapper in place. I am going to order one and see if it resolves the problem. Will try to post again if successful.

    [​IMG]
    Last edited by a moderator: Apr 24, 2010
  16. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,313
    Location:
    New England
    The, maybe bigger, design flaw (in my opinion) is that the flush lever isn't long enough to pull straight up. This means that it is always pulling the flapper from the side, making it harder for it to fall straight down all the time after being yanked sideways. A new flush lever arm might help, or buy one that works well with generally available parts!
  17. BocaDr1

    BocaDr1 New Member

    Messages:
    2
    Location:
    Boca Raton, FL
    YES! This is the part I have, but for the life of me I cannot figure out how to install it, and this appears to be just about the only Forum thread on the entire Web dealing with this. How do you attach that black plastic bar to the grooves on the back of the rectangular flush valve? The instructions say "with the prongs on the bar pointed toward the back of the flush valve, slide the pivot rod onto the valve." What does that mean? How do you slide the rod onto the valve? Is it supposed to snap into the groove? I tried that but wasn't sure just how much force to apply without knowing I was doing the correct thing, not wanting to end up breaking that plastic rod...Anyone know if snapping it in is the correct way to install it? Thanks.
  18. BocaDr1

    BocaDr1 New Member

    Messages:
    2
    Location:
    Boca Raton, FL
    I finally called Kohler...

    OK, so I called Kohler and they said definitely do not try to snap the bar into the groove! After they explained it to me, it seems the instructions printed on the packaging for the part are backwards - that's the problem...the prongs on that black plastic bar have to be pointing toward the back of the toilet and NOT the back of the flush valve, as they say in the instructions! If the prongs are pointing toward the back of the flush valve, they're actually pointing toward the front of the toilet. The black plastic bar has to be slid into the correct groove on the back of the rectangular flush valve starting at 1 end of the bar. So if the prongs are pointing toward the back of the flush valve, they're blocking the path of sliding the bar into the correct groove...they have to be pointing the opposite direction, toward the back of the tank. Then the bar just slides into the groove, you slide it back and forth a bit in the groove so you can then rotate the bar to reposition the prongs so they now point up. Then just attach the red rubber arms of the flapper to the prongs.

    It seemed to me a good way of estimating which was the correct groove to use for the plastic bar so that the flapper will seat correctly was to remove both red rubber flapper arms from the plastic bar and manually seat the flapper correctly over the drain opening in the tank then note with your finger which groove they appear to line up best with - maybe count the grooves from the bottom - and then position the plastic bar in that groove and reattach the flapper arms. In my instance, this new flapper in the correct position completely fixed the cycling problem with the Rialto.

    And just by the way, I found that intially the flush actuator arm was hitting the float valve assembly when I tried testing the flush after replacing the flapper and this was preventing the arm from raising the flapper enough to initiate the flush cycle. Turns out, with all the work I been doing back behind that rectangular flush valve trying to figure out the problem, I'd inadvertantly bent the entire float valve assembly forward, trying to fit my arm in there. When I gently forced the whole float valve assembly back toward vertical, that cleared the way for the actuator arm to run its full range, lifting the flapper fully so it then stays up while the tank empties and then drops right back down, correctly centered over the drain opening and the flush cycle works just fine now. Hope this helps!
    Last edited: Jun 24, 2010
  19. rolm

    rolm New Member

    Messages:
    15
    Location:
    Toronto, ON
    I solved many leaky flappers by simply taking emery cloth and sanding/cleaning around the flapper base and that has worked 99% of the time and the other 1% I cleaned and replaced the flapper. Should be an easy fix. As a side note I found the Kohler help line guys useless unless you are buying a new product or you are talking abought a product that is less then 6 months old.
  20. Samuel

    Samuel New Member

    Messages:
    1
    Location:
    Chicago
    Thank you!!!!!this was driving me crazy...I got a new flapper but had no idea that you have to insert the plastic rod APART from the flapper assembly into one of the grooves on the flush valve...THEN you put the flapper onto the rod....it seems that the directions should be much clearer....Thank you again!
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