I have an old toilet ( ~100 years old I think ) I need to replace the fill valve. The porcelain is very thick compared to modern toilets and the replacement fill valve stem is not long enough. Is there a product out there with a longer stem than the standard these days or is there a way to extend a fill valve stem ? I have thought of cutting off the stem from the old fill valve and connecting it to the new one using some kind of nut, but from what little I've read that nut might not exist. Any help would be appreciated. I really don't want to scrap the toilet, but that seems like the only other option.

do any threads show at the bottom of the tank?

not enough for both the nut that keeps it water tight from the bowl and the water supply connection.

sometimes you can come up with a thin metal nut up against the tank and gain a couple of threads for the water supply nut.
they do make a brass fill valve shank extension but in your case i don't believe it would help.

Thanks for the feedback. If anyone has a link to a place that sells the extension, I'd appreciate it if you'd post it. I looked and could not find it.

Right now the best plan I can come up with is to use the new plastic nut to connect the plastic threads to the old brass threads ( which I'll cut off of the old fill valve ). The plastic nut will doulbe as the inside seat and give the fill valve the stability it needs. I'll only have a thread or two for each piece so I plan to make sure they seat perfectly against each other before I put this thing together. I'll then use the old brass nut to connect to the brass threads on the outside of the bowl. I'll also do some things like maybe glue the two plastic pieces together and put a very thin rubber washer between the brass and plastic threads held together by the plastic locknut. If this leaks, it will leak inside the bowl.

If anyone knows where I can get a locknut with more than a few threads please let me know. Thanks.



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Is the new fill valve brass or plastic? If brass, I wonder if the ID is such, that a copper tube could be soldered into it and then use that "tail" of copper as an extension. Then the supply hose/tube can be connected to the tail by compression union(or soldering a threaded adapter to it).