The caliper bracket holds the pads and lets them slide, and it lives in a wet, salty environment - so it rusts. Rust in the wrong spot on the bracket causes real brake problems. Here is why bracket rust matters and how to deal with it.
Where the rust causes trouble
The problem spot is the abutment area where the brake pad ears rest and slide in the caliper bracket. Rust builds up under and around the abutment clips, taking up the clearance the pad needs to move. The pad then binds instead of sliding freely - a phenomenon related to brake hardware corrosion.
What it causes
A pad stuck by bracket rust drags, wears unevenly, overheats, and can cause a pull - similar symptoms to a sticking caliper. Rust jacking the clips also makes new pads rattle or bind. It is a top reason a fresh brake job is noisy or wears unevenly if the bracket was not cleaned.
How to fix it
At a brake job, remove the old abutment clips and clean the bracket rails down to bare metal with a wire brush and file so the new clips seat flat and the pad slides freely. Fit NEW clips (never reuse rusty ones), and apply a thin film of the correct grease on the contact points; see where to apply brake grease.
Prevention
Fresh hardware at every pad change and proper cleaning keep bracket rust from causing sticking pads. In salt climates it matters even more. Fit quality pads with a complete hardware kit on a cleaned bracket.