imo you should give the calliper/carrier a good scrub with a wire brush where it contacts the pad, whenever you change the pads.
the number of times ive had to sort out brakes that "didnt work properly" simply because the pad is fused solid with the calliper and doesnt move due to build up of dust and rubbish
the number of times ive had to sort out brakes that "didnt work properly" simply because the pad is fused solid with the calliper and doesnt move due to build up of dust and rubbish