Repairing Toto G-Max Flush

One of my toilets recently started filling the back water tank really slowly.   It sounded like it would fill for a few seconds, pause, then fill for a few seconds, pause... It was a Toto toilet with the G-Max fill valve.  As it turned out it was a bad gasket inside the valve and was a really easy repair.

• Shut off the water supply to the toilet.

• Flush the toilet to drain the tank, remove the cover and set it aside.

• Unplug the refill tube from the side of the valve -- simply unplug the tube from the its port on the valve.  Be gentle pulling this off as you can easily break the plastic where it connects.

• Remove  the valve's cap, and then set it aside.  It was easy to pull it as it just clips on close to the float bowl opposite the refill port.

•  Remove the valve's float arm, located on top of the valve, by holding the clips on the sides of the float arm and then lifting the float arm.

• Secure the valve with one hand and twist off the valve's cap with the other. Twist the valve counterclockwise to unlock it, and then remove it by simply lifting it.

Once I had disassembled to this point I could see the problem: on the underside of the valve cap there is a rubber gasket.  My gasket had worn out and was leaking.  As a result, water would shoot up through the gasket and prematurely fill the float bowl.  This would stop the water supply until the water drained out of the float bowl allowing the water to continue, repeating until the tank was full.

Rather than order an overpriced Toto part, I picked up the The Korky QuietFill Valve from Home Depot (also available at Lowe's) for about $10.  This is the complete assembly and is identical to the Toto G-Max.  Rather than remove the entire assembly, I simply took the valve cap from the Korky and used it to replace the damaged on the Toto. 

Total Time to repair was about 10min.