rear brake problem

[Spitz]

Hi i am new to this forum so be gentle with me , my car is a 2019 insignia sri 2.0 l

the problem is the rear left brake seems to bind ,disk is bit rusty ,which tells me something is wrong 

put new pads in ,but gets very hot and is binding ,any clues to fix this.?

[Vauxhall Owners Club]

Maybe the pads are sticking in the carrier  -  best to remove pads and see that they are free to slide sideways, if they are seized then they will need cleaning up (sometimes have too much paint on them) and copperslip to ensure they don't stick in the future