This work carries out complex modal analyses and optimizations to resolve an 1800 Hz front brake squeal issue encountered in a vehicle program development phase. The stability theory of complex modes for brake squeal simulation is briefly explained. A brake system finite element model is constructed, and the model is validated by the measurement in accordance with the SAE 2521 procedure. The key parameters for evaluating the stability of the brake system complex modes are determined. The modal contributions of relevant components to unstable modes are analyzed and ranked. Finally, in order to resolve the squeal issue, the design improvements of rotor, caliper and pad are proposed and numerical simulations are carried out. The obtained results demonstrate that the optimized rotor and pad design can alleviate the squeal issue significantly while the optimized clipper design could essentially eliminate the squeal issue. The analytical solutions obtained from the proposed pad design are validated by the experimental measurements.