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Toto GMax flush System

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  • Toto GMax flush System

    My toto flushes great, but when it fills the tank it slows then continues to fill until it overflow down the overflow tube.

    How do I adjust the gmax so it does not overfill the tank?



  • #2
    Re: Toto GMax flush System

    I have no success working on these fill valves. They are the first to clog against 400A Fluidmasters.

    I wish there was a better way to work on these.
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    • #3
      Re: Toto GMax flush System

      chances are the diaphragm is worn out. unless you actually moved the ballcock level by removing the locking clip and rotated the shank to make it taller. the ballcock is leaking, worn.

      you can remove the plastic cover by squeezing the sides and snapping it off. this will expose the actual float. try pushing down on the pivot to close the valve. if it still runs, replace the hunter diaphragm or just swap it out to a 400a fluidmaster and you'll be much happier.

      phoebe it is


      • #4
        Re: Toto GMax flush System

        There's a slot on the side of the G-Max. When the water level reaches it and flows in, the valve should shut off. The trick is positioning it where the valve shuts off with the water level about 5/8" below the overflow tube.

        You have to be careful with G-Max and Korky fill valves because too much pressure twisting on them and they'll break. If you need to reset the level, you have to remove the clip slipped in between the two tubular pieces first, then replace it when you've got it where you want it.

        You can take it apart to clean debris, and Korkys usually have an instruction sheet on how to disassemble them for cleaning. But if you try to remove the rubber seal inside the cap, you'll probably damage it.

        G-Max and plain Jane Korky are not identical - the G-Max has the proper refill amount for Toto.


        • #5
          Re: Toto GMax flush System

          If the G-Max valve is not shutting off, just pop a new assembly cap on it.
          They are about $2.50 at Lowes.
          Even a homeowner can replace the part without tools in less then a minute.
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          • #6
            Re: Toto GMax flush System

            yes the toto ballcocks are junk. the best fix is a fluidmaster pro45hr. this ballcock has the high refill option for the toto's and the kohler class 5.

            almost all side mount flush handles fail before a standard front mount handle.

            the toto g-max / red and power gravity/ blue flappers are very common here and do hold up.

            the biggest issue with the toto is the ballcock and toto has already attempted to replace it with another failed design.

            phoebe it is


            • #7
              Re: Toto GMax flush System

              Originally posted by TheMaster
              And 9 times out of 10 the cap doesn't repair it. You call ToTo for a new ballcock and they ask you 500 questions because they make too much Sh$t for even them to keep up with.

              ToTo is making their tank handles to FAIL....point blank. Lavelle sucks and always have. Toto realized this and are now using some other manufacturer for their ballcocks. The new ones are POS also.

              Get with it ToTO and PAY Fluidmaster to build you a ballcock that works. Quit making 500.00 toilets and using CHEAP TANK PARTS. Your on your last leg with this plumber.....I'm tired of working on your crap for free and waiting on parts that are toilet model specific.

              ADD 50 bucks to your already overpriced POS and provide a quality product for your customers and their plumber.

              Who did your enginners consult when picking out parts for your china????? The f'ing home depot and lowes??? Walmart??? Spend 3.00 more for a brass intenal stop for your toilet flush handle...ADD 4.00 to your already 9.00 flapper and use some quality rubber.........add 10.00 and use a fluidmaster.

              Wake the F up TOTO its not like you dont know these problems exist.

              Every customer I work for regarding a toilet replacement will know this about ToTo when I leave their home. TOTO dealers do not stock parts,the parts are crap for the tanks,the parts are not standard items,the parts are expensive. Over rated and over priced for what you get.
              Thanks Master, I needed this verified. What do You thik of Gerber ?
              I can build anything You want , if you draw a picture of it , on the back of a big enough check .


              • #8
                Re: Toto GMax flush System

                ... I actually keep toto parts on my truck, and two of the suppliers in my area who handle toto keep a good selection of factory parts in. Now, they aren't cheep by any means, but they are available for me. which is good, because i'll sell a toto anytime I can.
                Originally posted by NHMaster3015
                No, it's not rocket science, it's plumbing and unlike rocket science it requires a license.