Changing pads (short manual / suggestion):
- demount the caliper
- take off the old pads (remove bolts / spring, push out depending on model)
- clean the caliper complete (e.g. with teeth brush an detergent), check wear
- lubrify the pistons with ATE piston paste (e.g. with a 2nd brush)
- push back the pistons
- lubrify the edges and the back side of the pads with copper paste (do not lubrify friction surface)
- put the pads into the caliper like the old ones were in
- assemble the caliper to the bike, check function
Optional depending on caliper:
- check wear of bolts and springs, if is: replace
- use ceramic paste instead of copper paste (special calipers according to producer)
Always use fresh brake fluid and take care of a clean brake disk.