I have a Toto toilet that I have been using for 6 years.A few days ago, I noticed that the level in the bowl after a refill was very low. I checked the fill tube in the tank and it was attached and working properly. If I add water to the bowl, the level will stay until it's flushed again so,I've ruled out a leak. It seems that whatever water is fed into the overfill tube while the tank is filling is draining out of the bowl as it tries to fill.
I have flushed and refilled with the bowl fill tube connected and not connected and there is a difference of the amount of water in the bowl. I think I have checked everything I could think of. Any ideas?
Thank you so very much.
Ken

What's the tank level? It should be 1/2" under the lip of the white overflow tube. Do you have a float ball ballcock? Back to U. Tom

The level is proper. Toto contacted me telling me to check if the fill valve itself was clogged thereby not allowing the right amount of water to get to the bowl. They said to take it apart and clean it.
This was my reply to Toto:
"I have done what you suggested and found no dirt or blockage. After making sure everything was clean, I filled the tank. This time, I flushed with the small refill tube in a measuring cup. After the tank was full, the measuring cup had 28 ounces of water that should have gone into the bowl. I then slowly poured the water directly into the bowl and it seemed to drain out as I poured it in. I got 2 quick "burps" from the bowl but, still a very low level. Then, I repeated this and pored the 28 oz. of water into the refill tube. Still a very low level. It seems to me that as water goes in to refill the bowl, it just drains right out. If I wait a minute and then fill the bowl manually, the bowl accepts and keeps the water. It seems to me that after the flush cycle has ended and the refill process has begun, the bowl is just letting whatever water going in to fill it drain away. Almost as if there was a drain valve not closing completely even though I know there is no valve.
Any other suggestions?
Thank you so very, very much for any help you can offer. I'm usually very good at repairing things but this one has me stumped!"

There could also be a factory defect in the bowl. Sometimes in casting the bowl there is a small bubble in the china. Instead of junking the bowl the manufacture will put a porcelain patch over the hole and send it on through. On occasion the patch will fail allowing the water to seep out of the bowl. If that's the case you would have a full bowl after you flushed and the bowl filled but some time later you would notice a drop in the bowl level. The only other thing might be if you dropped something in the bowl and cracked it. If you're worried about where the water's going, in both cases it drains back down into the sewer and not under the bowl on the floor. To check the bowl must be pulled, filled and put up on saw horses. You can then see if there's any leakage from the bowl.
Good luck, Tom

My problem is the opposite. The bowl doesn't fill after flushing and if I fill it manually, it will stay full.
Back to the drawing board, I guess.

Thanks though

Call the Toto engineers. This has just got to be a defect in the bowl.
Any other experts out there ever tun into this? If so [please respond. Tom