If you do your own brake jobs, chances are you've switched to the newer ceramic-style brake pads. They're much cleaner and quieter than semi metallic pads. But they don't dissipate heat as well, and that high heat can degrade the grease in caliper and pad slides. So it's critical that you use synthetic high-temp grease to lubricate the caliper pins, pad abutments and pad slide hardware.
Now there's a new type of grease made especially for ceramic brake pads (one choice is Permatex No. 24125 Ceramic Extreme Brake Lubricant; about $17 for 8 oz. through our affiliation with amazon.com). The high-temp lube contains ground-up ceramic particles that act like ball bearings to ensure proper caliper and pad movement. Apply it to all slide areas as shown.