I just took apart the valve inside of my toilet to fix a crack in the floater. It's a Fluidmaster 300:
When I put the thing back together and turn the water back on, no water comes out of the refill tube. Instead, it squirts out of the top of the red cap where the black floater connects.
Underneath that red cap is a rubber diaphram, which i've pulled out and inspected. It's in good shape. it has a little nipple in the middle where a tiny stream of water can come out, and water is coming out of that, but not the refill tube. Anyone know what's going on here?
Edit: I found a little pin in the bottom of the toilet. Is this supposed to go in the nipple of the seal? Looking at the valve, I can't even understand how the arm raising could possibly shut anything off! I feel like I just discovered a glitch in the matrix or something.