Bolted to the steering knuckle, a brake caliper has two basic jobs: housing friction material ... caliper slide pins or shims. Bad caliper hardware will also cause brake pads to wear unevenly ...

The brake caliper is a housing for the brake pads and is responsible for transforming hydraulic pressure into mechanical force. When the driver pushes the brake pedal, the hydraulic pressure from the ...

One likely cause for the noise, reports GM, is a worn lower brake caliper pin bushing. To make a proper diagnosis, take the vehicle on a road test to see if you can get the rattling noise to reappear.