Hi all.

I've noticed recently my toilet has been making a quiet sound of water
refilling, even when full.

After a flush and a full refill of water into the cistern (loud) the unit
makes the sound it does when refilling, but more quietly.

I take the lid off the cistern and the black plastic pump thingy inside
sounds like its passing water or something, just queitly though, I cant put
my finger on it.

Any ideas anyone?