Toto Drake difference between fast & full flush?

[HomeRepairGuy]

Have a Toto Drake CST743 toilet which I believe is a 1.6 GPF toilet.

I previously replaced the flapper with a Korky flapper. That flapper developed a slow leak (after about a year of use) so I just replaced it with a Toto THU500S flapper.

The THU500S is an adjustable flapper so I want to adjust it for a proper fast flush. The directions say to turn off the water supply and to do a fast flush with the old flapper and mark the water level with a pencil. Then install the THU500S flapper adjust it so that the fast flush drops the water level to marked line. But the Korky flapper was not adjustable so I don't know whether it's fast flush was proper or not.

I adjusted the new Toto flapper and the fast flush is 67% of the full flush. Is that about right for a fast flush?

 

[Terry]

It's more important to look at the water in the bowl. The water needs to flush , but not over and over again, and for for a long time.
The recent bowls from TOTO work with 1.28 gallons, which work with both the 1.28 and the 1.6 tanks.

 

[Sponsor]

 

[HomeRepairGuy]

It's more important to look at the water in the bowl. The water needs to flush , but not over and over again, and for for a long time.
The recent bowls from TOTO work with 1.28 gallons, which work with both the 1.28 and the 1.6 tanks.

Thanks Terry. The fast flush only flushes one time and seems normal so I guess it's OK.

Just for additional info, when you adjust the fill valve, how far below the top of the overflow tube do you usually adjust the water level? (I'm using a Fluidmaster fill valve)

 

[Jadnashua]

Unless that Fluidmaster valve has an adjustment available for the water going out the hose to refill the bowl, it is probably wasting lots more water than the toilet was designed for.

But, as to your question about the level below the refill tube's top, if there isn't a mark on the tank, figure about 1/2" or so. The goal is to get the tank refilled just as the bowl is full. While overfilling the bowl won't hurt performance, it does waste water. If the bowl isn't full, it tends not to flush well.

The OEM fill valve had a calibrated restrictor in it to ensure the balance between tank and bowl fill was correct. A new fill valve must either match that OEM value, or be adjustable to minimize water use and ensure proper performance.

 

[HomeRepairGuy]

Unless that Fluidmaster valve has an adjustment available for the water going out the hose to refill the bowl, it is probably wasting lots more water than the toilet was designed for.

But, as to your question about the level below the refill tube's top, if there isn't a mark on the tank, figure about 1/2" or so. The goal is to get the tank refilled just as the bowl is full. While overfilling the bowl won't hurt performance, it does waste water. If the bowl isn't full, it tends not to flush well.

The OEM fill valve had a calibrated restrictor in it to ensure the balance between tank and bowl fill was correct. A new fill valve must either match that OEM value, or be adjustable to minimize water use and ensure proper performance.

Thanks jadnashua. The toilet fill is 1/2 inch below the top of the overflow tube so that looks good. And the bowl is just filling to the top when the fill valve shuts off so that looks good also.

Thanks for your help,
HRG