Diagnosing leaking toilet

Discussion in 'Toilet Forum discussions' started by melman, May 11, 2014.

  1. melman

    melman New Member

    Messages:
    8
    Location:
    Az
    I recently replaced the tank on a 1993-ish Crane toilet. (My tank was cracked at the handle opening, and a neighbor was replacing his old toilets, same model, so I salvaged his old tank.) The new-to-me tank has a full Korky rebuild kit (from Lowes) in it. Not sure why he replaced the original flush valve, mine still have the original flush and fill valves, still working great. But, whatever.

    I installed the tank with a new tank-to-bowl seal and bolts, filled it, and left the water off to check for leaks. Sure enough, there is a very slow leak (it drains out over a few days). No water on the floor. I replaced the Korky flapper which was showing signs of wear, with a new Fluidmaster flapper, and this leaked faster. I then installed a Korky flush valve repair kit which is a flapper and a glue-on flush valve seat. I think it's back to leaking very slowly.

    Before I give up and replace the entire flush valve, is there anything else I might check? If the gasket between the flush valve body and the inside of the tank was leaking, it would probably leak onto the floor, or into the bowl and onto the floor. Wouldn't it? Hard to guess at where such a leak would run to. Again, there is absolutely nothing on the floor. Perhaps there is a pinhole leak in the overflow tube. I don't recall how far down the tank drained after fully leaking out. Down near the level of the flapper, but I didn't note exactly where.

    Fill tube is above the overflow tube, it's not siphoning.

    All ideas appreciated.
    Last edited: May 24, 2014
  2. wjcandee

    wjcandee Wise One

    Messages:
    1,769
    Location:
    New York, NY
    You're looking in the right spot. I might pull off the Korky rubber ring around the valve seat that you just installed and brillo the seat and see if that helps. I would stick with the Korky flapper.

    Also, make sure that there's enough slack in the chain that it's not preventing a complete seal. I have seen that before. Also, on some models of toilets (a very, very few), when you put the lid back on it can move the flush handle a smidge, again causing a very slow leak. One or two links of chain slack should be sufficient. In fact, sometimes folks put in too much slack, and a link of the chain gets stuck below the flapper. These are just random thoughts, because you seem to have the right idea about how the flush valve works...

    One other possibility is that the overflow riser might be cracked. I have seen that in a few cases on here. But if the toilet drains down all the way to the bottom, that's unlikely.

    One other thing to check is whether you have the refill hose stuck down in the overflow riser, which will create a siphon and slowly drain the tank. It should be "daylighted" on a clip above the top of the riser. Sounds like you would know this already, though.

    Let us know how this works out for you, and post a picture on here if you like. Sometimes we can see something in a photo.

    I used that Korky rebuild kit on four toilets in our house, and it's a good one, so that's not -- per se -- the problem.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,264
    Location:
    Cave Creek, Arizona
    You have to let the water drain down as far as it is going to go. THAT will be where the leak is located, whatever it is. Of all the possibilities, a bad flush valve would be the last one I would consider. I have only changed a few flushvalves in the past 60 years.
  4. Wallijonn

    Wallijonn Member

    Messages:
    125
    Location:
    Arizona
    You have a Crane toilet. You changed the tank. The problem started. Can you use all the parts from the old tank in the replacement tank, to see if the problem goes away?
  5. wjcandee

    wjcandee Wise One

    Messages:
    1,769
    Location:
    New York, NY
    There is nothing special about Crane parts.
  6. melman

    melman New Member

    Messages:
    8
    Location:
    Az
    Those parts are over 20 years old. For sure, if I took them out of the old tank and moved them, I'd either break them or they wouldn't seal.

    If I have to take the tank off again, I'll put in new everything.

    And on the topic of "new everything" and flappers and such. My old stuff had a fill valve Coast, "1B1 Master Mark III". The flapper is a solid plastic frame, a raised center chamber that holds air, a rubber ring to seal it, and a float on the chain. Something like this:
    http://www.coastproductsonline.com/...ER-W-1125-BEADED-CHAIN-FLOAT--16GPF_p_34.html
    I still have all the original parts in one toilet and it works great. I have the float adjusted so it closes right at the moment of flushing, or slightly before. It uses very little water. Being installed in late 1993, I don't know if these are 1.6 gpf's or not. They aren't marked as such.

    When the flapper seal ring began to stick in my old tank (and this is why I cracked it, I was too stupid to fix it and I forced the handle, cracking the glaze), I replaced with a Korky flapper. I have never been able to get the "timing" right. The Korky wants to open all the way up, and stay up until the water line comes down to it. It stays open for several seconds after the flush, so it wastes a lot of water and often double flushes. Any solution for this? I could try to attach weight to the flapper, or I could lower the fill level by a lot.

    Anyway, if I have to buy new parts, I'd like to get what works. But HD and Lowe's only carry Fluidmaster and Korky and their flappers look the same to me. I'd buy the correct Coast parts if anyone sold them locally.
    Last edited: May 24, 2014
  7. melman

    melman New Member

    Messages:
    8
    Location:
    Az
    Yesterday, I put coloring in the tank. Since then, it's leaked down about 1.5 inches. The bowl water is colored, but the bowl is bone dry above the water line, no tracks of where the leaking water came in. It's that slow.


    I'll let it drain all the way down again and see where it stops.
  8. wjcandee

    wjcandee Wise One

    Messages:
    1,769
    Location:
    New York, NY
    Good. It came in through the bottom most likely (siphon jet).

    As to the flapper, if it's not closing quickly enough, you can use this Korky one: http://www.lowes.com/pd_579153-868-...t=korky&pl=1&currentURL=?Ntt=korky&facetInfo=

    That one can be adjusted to close faster or slower. Very easy to use. The original, basic Korky flapper is designed to run the water down pretty far, because it's for the old toilets. Korky also makes one with a float, also to adjust when the flapper closes, but I like this new one.
  9. melman

    melman New Member

    Messages:
    8
    Location:
    Az
    D'oh! Of course.
  10. melman

    melman New Member

    Messages:
    8
    Location:
    Az
    After 4 days, I think the water level has stabilized at about the level shown below. Will wait a couple more days to be sure. This is getting a little baffling. I suppose the tube could have a pinhole at that level. Could the leak be at the gasket under the flush valve, and the remaining water in the tank no longer creates enough pressure to leak through? (I'm still not clear on how the water would get into the bowl, but I suppose it's possible.)

    I think I can rule out the flapper, which should leak more with less water pushing it down, and continue to leak until the water line reached it.

    Attached Files:

    • a1.gif
      a1.gif
      File size:
      71.9 KB
      Views:
      91
    Last edited: May 17, 2014
  11. Terry

    Terry Administrator Staff Member

    Messages:
    14,775
    Location:
    Bothell, Washington
    Any water that goes past the flapper, down the overflow tube, or through the overflow tube winds up in the bowl. It's how the bowl gets it's water.
  12. melman

    melman New Member

    Messages:
    8
    Location:
    Az
    But Terry, what if the leak is not in any of those places. Maybe it's under the gasket that's between the flush valve body and the inside of the tank. Underneath the tank, the sponge ring should be sealing up pretty tightly, since it's 2 inches of foam compressed down to 1/4 inch. If that's where the leak is, the water must be following a path down the outside of the flush valve outlet and into the bowl. Since it's not dripping on the floor. Just a theory.

    In any case, I think I spoke too soon. The water level is still going down. When the tank was full, maybe 1.5 inches per day. With less water in the tank, much more slowly. But it isn't done yet.
    Last edited: May 17, 2014
  13. melman

    melman New Member

    Messages:
    8
    Location:
    Az
    Well it's almost a week later and the water level did indeed stop at the level in my picture.

    Bought a full kit at the plumbing supply (Fluidmaster PRO45K), will put it in over the weekend. This kit has a flapper with an adjustable float.
    Last edited: May 24, 2014
  14. melman

    melman New Member

    Messages:
    8
    Location:
    Az
    All done. Korky overflow tube was leaking at the joint below the arrow in the picture.

    Hope this helps someone...
  15. wjcandee

    wjcandee Wise One

    Messages:
    1,769
    Location:
    New York, NY
    Cracked overflow riser. Rare but it happens. Yours is the third I have seen on here in the last three years. Usually, a slow-leak tank is caused by something simpler.

    Glad you are back in business! Congratulations!
Similar Threads: Diagnosing leaking
Forum Title Date
Toilet Forum discussions Leaking tank/flapper valve Jun 29, 2014
Toilet Forum discussions leaking disc from american standard 4049 tank May 2, 2014
Toilet Forum discussions Leaking Toilet. Tried Everything... Apr 8, 2014
Toilet Forum discussions Toto Fill Valve Leaking Mar 22, 2014
Toilet Forum discussions leaking toilet Jan 8, 2014

Share This Page