NHTSA Complaint #11707945 — 2010 TOYOTA PRIUS

On November 25, 2025, at approximately 11:45 p.m., our 2010 Toyota Prius experienced a braking system malfunction during normal operation. The brake pedal required significantly increased effort and the vehicle exhibited reduced braking performance, indicating a loss of brake power assist. The vehicle required increased stopping distance, creating an immediate risk of a collision. At the time of the failure, multiple warning indicators illuminated simultaneously, including the brake system warning, ABS warning, check engine light, battery warning, steering warning, tire pressure warning, and vehicle stability control/slip indicator. There were no warning lamps or abnormal symptoms prior to the failure. The failure was determined to involve the brake booster pump assembly, a component responsible for maintaining hydraulic brake assist pressure. This component is known to experience internal accumulator housing degradation, which can allow nitrogen gas migration into the brake fluid and result in partial or complete loss of brake assist. The affected component remains available for inspection. Following the incident, an authorized Toyota dealership inspected the vehicle and reproduced and confirmed the condition. Service records indicate the brake booster pump assembly had previously been replaced under a Toyota safety recall. Despite this prior recall repair, the same component failed again after approximately 41,000 miles of service, demonstrating that the recall remedy was ineffective. As a result of this failure, the vehicle was rendered unsafe to operate. Despite dealer confirmation that the malfunction involved a previously recalled safety component, corrective repairs were declined, with warranty limitations cited rather than addressing the repeat safety-related failure.