thin alloy sheet behind frount pads needed or not

i have a 97 vfr 750fv put new frount caliper seals in found these thin tin sheets with another bit behind the pads what is this and what does it do with new pads it seems to make them bind ? any ideas help

 

They serve several purposes. The main one being reduction of braking noise, which is why they are usually called anti-squeal shims. They also act as insulation/isolation between the pads and the calipers, which slows down brake fade due to over heating.

If the new pads are OEM, I would make sure that the pistons are properly reset.

 

i have rebuilt both frount calipers new seals dust seals and pistons ebc sintered pads hey were a sod to bleed hopefully all sorted now no more binding

 

Dija also clean and regrease those slider pins??