Whenever I flush, I hear a loud squeak. It sounds like metal hitting metal. What could it be?

That's a new one, never heard of that before.
Exactly when do you hear the squeak, when you push the flush lever, when and during the actual flush, or when the tank starts refilling.

That's a new one, never heard of that before.
Exactly when do you hear the squeak, when you push the flush lever, when and during the actual flush, or when the tank starts refilling.
It squeaks when I press the flush lever.

[QUOTE=nelle07;3528725]It squeaks when I press the flush lever. It sounds like a high pitched squeal. Once the lever is pressed all the way down, the toilet starts refilling, the squealing stops.

What kind of flush valve do you have. Remove tank top and flush. Watch for moving parts and see if you can determine which part is squeaking. Post picture of flush valve if other than flapper valve.