If it's the Korky style, it's decorative.
I just purchased a Toto Drake and upon removing the tank from the box, the blue cap that fits on top of the fill valve fell off. This is the piece that has the "G-Max" lettering on it. It looks like it fits onto 2 pins on the fill valve to hold it in place. Well, these pins (both of them) have broken.
Can someone tell me if this cap is just decorative? Is it used to deflect incoming water back down into the tank like the FluidMaster fill valve? Will it have water pressure forcing up against the underside of this cap? I'm wondering if its just sufficient to put a dab of silicon to hold this cap in place. Can anyone provide some help?
IF it is needed to deflect water, then the fill valve is defective and should be replaced, otherwise it is just decorative to conceal the mechanism.
Thanks Terry and hj for your responses.
Since I was on an errand into town I decided to bring the tank back to the supply house. They were very good about it and promptly exchanged the whole tank set, not just the fill valve.
I'm a bit concerned about the quality of the Toto toilets I purchased, though. I bought 2 Drakes (ST743S tank, C744EG bowl) because I wasn't sure what kind of quality I would get from the box stores. However, the first tank had the problem described above and as well, the bag of hardware that came with the tank was missing one of the plastic bolt cap holders. The second tank had a warped flush lever so that the flush valve flapper was never sitting closed; I had to drop the chain a notch before the flapper would stop water running into the bowl (I didn't want to risk bending that metal flush rod). Also, this second tank had a lid that wobbled; it did this when set atop of either tank.
These were all in sealed boxes when I picked them up so I don't think I got rejected goods from a previous purchaser.
Given what I've read about the quality of Toto toilets, my experience seems to be a statistical outlier at the other end of the spectrum. I'm hoping the performance of these toilets will make up for this disappointing out-of-box experience.