The contact owns a 2013 Ford Fiesta. The contact stated that while driving at an undisclosed speed, the brake pedal was depressed; however, the vehicle failed to stop as intended. The contact stated that the brake pedal was depressed several times before the vehicle came to a stop. In addition, the contact stated that the vehicle almost crashed into another vehicle due to the failure. The vehicle was taken to an independent mechanic, where it was diagnosed with brake master cylinder and vacuum brake booster failure. The contact was informed that the brake master cylinder and the vacuum brake booster needed to be replaced. The vehicle was not repaired. In addition, the contact was informed that a brake fluid leak was not visible. The contact stated that the low brake fluid warning light was illuminated, and the brake fluid was refilled two days prior to the failure. The dealer was made aware of the failure but provided no assistance. The manufacturer was made aware of the failure, and a case was filed. The contact referenced an unknown recall; however, the VIN was not included with the recall. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was approximately 40,000.