Some Mazda CX-9 owners report experiencing brake squeaking and grinding issues that may stem from several underlying causes. Brake squeaking is often attributed to high-frequency vibrations when brake pads do not slide smoothly over the rotors, which can be exacerbated by brake dust, temperature fluctuations, or overly smooth rotors and pads. While applying anti-squeal compounds may provide temporary relief, the problem can persist if not addressed at its source. Additionally, grinding brakes, which produce a lower-pitched sound, may indicate worn-out brake pads and require immediate attention to prevent further damage to the braking system. Even after replacing the rear brake pads with NAPA Adaptive One pads, some owners find that squeaking and grinding noises continue, suggesting that the root cause may extend beyond the pads themselves. Proper alignment of the brake rotors with the new pads is essential, and a thorough inspection of components such as the brake rotors, calipers, and brake booster may be necessary to resolve these persistent issues effectively.