thin metal piece left off front disc pads

[jeffchas]

The mechanic left off the thin metal plate that fits between the piston and the back of the pad. What is the metal plate for and what problems can occur if left off. thanks, Jeff

[usmc1968]

There's a piece of backing paper on the metal piece that came with your brake pads. You are suppose to peel it off and stick it to the back of your pad. It's there to keep your brakes form squealing. It should be installed, but if not don't worry about it.