What is the use of brake hardware kit? Is it okay to just toss them out when install new brake? Or I should get new ones to put on? What if I installed the brakes without hardware kits? Sorry about the series of questions.

 

I think the hardware kit is the brass clips and flat springs that you see that fits on the cliper where the pads ride on. You're supposed to replace them when you replace the pads. I didn't, just cleaned them, but next time I will replace them. They allow a smoother surface for the pad backing plate to slide on. You should lube it. Plust the spring like things on it keeps the back edge of the pad more away from the rotor to reduce vibrations. Also use brake lube on the shims too.