I was replacing the brakes tonight on my 04 f150. I lost of the u shaped metal spring/wire that is inserted into each of the brake pads. Does anybody know what this is called so I don't sound really dumb going to the auto parts store asking for 1? Is it a part I can live without?

 

its an anti rattle spring.

 

I think NAPA carrys a new brake install kit of parts.
It is nice to replace all new.