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 Flushes
Step 1: Turn Off Water
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.
Step 2: Remove Top of Fill-Valve Assembly
Remove the blue cover at the top of the fill-valve assembly and press the float arms inward to remove the float.
Step 3: Remove Cap From Valve Assembly
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.
Step 4: Remove Strainer From Center Tube
Pull out the center tube and use needle-nose pliers to gently remove the strainer from the tube.
Step 5: Reassemble Strainer and Cap
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 align with the float chamber and refill port on the side of the valve body.
Fill Valve Runs Constantly
Step 1: Turn Off Water
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.
Step 2: Clean the Seal
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.
Step 3: Flush the Toilet
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.
Step 4: Locate Flush Valve
Locate the flush valve and note the position of the colored button on top of the flush valve. Remember this for reassembly.
Step 5: Pull Out Valve Assembly
Turn the upper portion of the valve assembly counterclockwise and pull it out.
Step 6: Rinse Black Seal Gasket
Remove the black seal gasket from the base of the flush valve and rinse it with clean water.
Step 7: Replace Gasket on Valve
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.
Step 8: Turn on Water and Flush
Turn the water supply back on and flush the toilet several times to check for leaks.
Weak Pressure When Flushing
Step 1: Open Water Supply Valve Fully
Ensure that the water supply valve is fully open. The toilet may not flush as it should if it is not receiving enough water.
Step 2: Inspect Valves for Damage
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.
Step 3: Align Tank Lid Properly
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.
Step 4: Plunge the Toilet
Use a plunger 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.
Step 5: Call a Plumber
Contact a plumber if this doesn't resolve the problem. The plumber can determine whether your venting pipes are obstructed or your home has inadequate water pressure, which for the TOTO G-Max flushing system should be 20 psi.
Renee Miller began writing professionally in 2008, contributing to websites and the "Community Press" newspaper. She is co-founder of On Fiction Writing, a website for writers. Miller holds a diploma in social services from Clarke College in Belleville, Ontario.