You need to install the
Brake Caliper bracket, and the caliper bracket bolts, then install the brake pad retainers to the brake caliper bracket, apply a thin coat of silicone grease (GM P/N 18010909 or equivalent) to the brake pad retainers where the brake pads contact the brake pad retainers, then lubricate the brake caliper bolt bushings with silicone grease (GM P/N 18010909 or equivalent), next install the brake caliper bolt bushings to the brake caliper bracket, and lubricate the brake caliper bolt boots with silicone grease (GM P/N 18010909 or equivalent), followed by installing the brake caliper bolt boots to the brake caliper bracket and installing the brake caliper.