GMax flush valve problem

Discussion in 'Toilet Forum discussions' started by wrfostersmith, Feb 11, 2008.

  1. wrfostersmith

    wrfostersmith New Member

    Feb 11, 2008
    Hi There --

    We have a Toto Carlyle with a G-max flush valve. Periodically, after we flush, the tank fails to fill up -- the water just doesn't turn on (eerie silence after the flush is finished). This doesn't happen all the time, just now and then (4-5 times a week). If we take the lid off and nudge the upright part of the valve a bit, the water usually comes on, but I don't know what's making it do that. I'm not familiar with how this valve works (no floater, etc.) and I don't want to take it apart if I don't have to. Is there an easy fix?

    Thanks for any advice you can give --

  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    The valve is made to come apart easily. You may have some debris in the valve assembly, or the cap may need to be replaced - both are easy to resolve. Pop the top cap off (after shutting off the supply!), squeeze the sides of the float that is now exposed to remove it, then 1/4-turn the cap off after removing the rubber hose. You can then pull out the guts. Clean off the screen, and put it back. That may solve the problem. If not, pick up a new cap for a Korky at Lowes, or a plumbing supply store for around $3 and put it on in place of the old one. You'll have essentially a new valve. Check out the Korky website for pictures and instructions.

    Last edited by a moderator: Feb 11, 2008
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  4. wrfostersmith

    wrfostersmith New Member

    Feb 11, 2008
    Thanks for the help! I'll try it.
  5. Briarius

    Briarius New Member

    Jun 16, 2005
    Dallas, Texas
    Float arm drain valve hole needs cleaning too

    Thanks for the information on cleaning the GMax. In my case, the reason the GMax was slow to fill was because the small drain valve in the plastic "box" around the float arm was sticking. It appears the drain valve releases the water around the float arm when the toilet flushes, thus dropping the float arm and opening up the water valve. Since the box stayed full of water, the float arm never lowered. Eventually, the weight of the water forced open the drain valve and the toilet refilled. So, check the small drain valve as well when you're cleaning the rest of the mechanism.
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