A chirp would be an indication that something is not right.
This link below has cleaning instructions for the valve.
I just installed a new korky QuietFill toilet fill valve and I noticed that just as it shuts off, it gives of a quick squeak or chirp. Is this normal? It's very annoying since this product claims to be the "proven quietest" fill valve available, and I'm certain my old ballcock didn't make this noise.
If it is not normal, any clues as to how I can make it go away?