Toto manufactures several models of toilets with a variety of features. The G-Max flushing system includes a wide flush valve and trapway for improved flow to draw water into the bowl rapidly, and then away again with added force. Because of this powerful siphoning, Toto G-Max toilets ensure that what you flush stays flushed. The parts within the fill and flush valves that power the G-Max flushing system may become dirty and this can affect the performance of the flush system.
Toilet Runs between Flushing
Turn off the main water supply to your toilet and flush. The flush-valve seal gasket may be dirty if the toilet runs on and off between flushes.
Remove the blue cover at the top of the fill-valve assembly and press the float arms inward to remove the float.
Hold the fill valve with one hand, while twisting the cap about an eighth turn counterclockwise with the other hand to pull it off the valve assembly.
Pull out the center tube and use needle-nose pliers to gently remove the strainer from the tube.
Run the strainer and the cap under water to clean them and reassemble, placing the strainer back into the tube and the tube in the valve assembly. When properly assembled to the valve body, the ribs on top of the cap aligns with the float chamber and refill port on the side of the valve body.
Fill-Valve Runs Constantly
Turn off the main water supply and remove the tank lid. If your G-Max toilet is running without flushing, the fill valve seal may be dirty.
Open the valve cap and clean the seal using a damp cloth. Replace it on the fill-valve assembly and turn the water back on.
Turn off the water supply and flush the toilet if cleaning the seal doesn't resolve the problem. The flush-valve gasket may need cleaning as well.
Locate the flush valve and note the position of the colored button on top of the flush valve. Remember this for reassembly.
Turn the upper portion of the valve assembly counterclockwise and pull it out.
Remove the black seal gasket from the base of the flush valve and rinse it with clean water.
Replace the gasket on the valve and insert the valve body back into the toilet tank. Turn it so that the colored buttons on top of the assembly are in their original position.
Turn the water supply back on and flush the toilet several times to check for leaks.
No Flush or Weak Pressure when Flushing
Ensure that the water supply valve is fully open. The toilet may not flush as it should if it is not receiving enough water.
Inspect the flush and fill valves for damage. If either shows damage such as cracked or broken gaskets or caps, contact the manufacturer for replacement.
Remove the tank lid and replace it on the toilet if your flush buttons stick. If the tank is not aligned properly, the flush button cannot operate.
Plunge the toilet to clear any obstructions in the line. If there is something even partially blocking the flow of water, this may affect the toilet's ability to flush properly.
Contact a plumber if this doesn't resolve the problem to determine if your home has adequate water pressure, which for the Toto G-Max flushing system should be 20 psi, or if your venting pipes are obstructed.