wrote in message
ups.com...
About two weeks ago our downstairs toilet started squeaking while
the
tank refilled after every flush. The squeak got louder the past
couple
of days and yesterday I noticed that water is leaking into the
toilet
bowl. We have Hunter 528 anti siphon system in the tank. It looks
like
this:
http://www.plumbingmart.com/lavellefillvalves.html

Should I replace the whole valve or is there an adjustment I can
make
to bring the water level below the overflow pipe. I'm a newbie so
please be descriptive in your replies.

Check whether the valve shuts off the water completely by lightly
lifting the float. If it doesn't, then there is probably a replaceable
valve seal. The common valve seals are easily available at Lowes or
Home Depot, or any plumbing supply place. You might need to contact
the manufacturer for this one to find a supplier.

As mentioned by others, there is an adjustment, but if the seal leaks,
adjusting it won't help.
If the water rises, and the float rises, but stops with the water
still rising, that is another sign of a seal problem.

Bob