I've installed several Toto Drake toilets over the years and they've always performed well, UNTIL RECENTLY when the toilet bowl on a recent install wouldn't fill completely.

I spent A LOT of time trying to figure out what was wrong. I've checked that the floor was level, I tried adjusting the fill valve and got it set up exactly the same as another Toto Drake toilet in our house (which didn't have these problems). I could not diagnose or figure out why this bowl wasn't filling! I wasn't sure if it was a defect with either the tank or bowl.

I searched and found various solutions in forums and other YouTube videos, but none of these suggestions helped me.

I finally shot a video (similar to the one you see above) and sent it to Toto Customer Service. About a week later, I got an email response telling me the problem: the black fill tube (coming off the fill valve) was supposed to go into the larger white flush valve tube and NOT into the tank.

As soon as I made this simple adjustment, it fixed the problem.

This is the toilet in the video: https://www.totousa.com/drake-two-pie...

Good luck!