What causes brake squeal when backing up?

Brake squeal when backing up is often caused by a combination of factors, including dust, dirt, or debris trapped between the brake pads and rotors, which can create friction and noise. Additionally, worn brake pads or insufficient lubrication on the brake components can contribute to the squealing sound. Furthermore, the design of the brake system, including the materials used in the pads, can also influence the occurrence of squeal during reversing. Regular maintenance and cleaning can help minimize this issue.