Toto Drake fill valve leaking.

Need a little help here. My Toto Drake fill valve is leaking and I need to replace it. Called Toto and they send me a TSU18A that looks just like the one in my toilet. Problem is I have no instructions and can't seem to find them anywhere. This is the G Max with the white screw.

The Drake uses a TSU24A not a 18 the 18 is for the G-Max 1pc toilet.
http://www.guillens.com/Toto/pdf/GMax%20FV%20manual.pdf