An adjuster system for adjusting the position of a brake pad relative to a brake disc so as to maintain a suitable running clearance between the pad and disc in a disc brake. The system comprises a manual rewind apparatus to reset the position of the brake pad when replacement thereof is required. The manual rewind apparatus has a transmission path extending from a rewind tool engaging portion to a brake pad engaging portion of the system. The manual rewind apparatus is configured such that when a rewind torque above a pre-determined torque is applied to the transmission path by a rewind tool, no damage is caused to components along the transmission path.