NHTSA complaint #11546725

Owner complaint summary

On 9/23/23 at approximately 4:10pm, my Rivian R1T suffered a catastrophic failure of the left rear brake. After exiting the freeway, I was slowing for a traffic signal primarily using the regenerative brake feature. I applied light pressure to the brake pedal which initiated a left rear brake failure. I attempted to move the truck out of the traffic lane. The left rear wheel was locked and would not roll. Upon removing the aero cover from the wheel, I observed the brake caliper in an abnormal position. The wheel had a sizeable hole in the middle of it. I surmised that the brake caliper shifted position during braking and damaged the wheel. The vehicle was towed to the Rivian Service Center in Phoenix, Az. A representative at the Service Center has told me that the wheel would not roll because the brake caliper shifted into the center of the wheel preventing it from turning. They have withheld further information about the root cause until they can investigate further. Had this event occurred at higher speeds, I have no doubt it would have caused a loss of control of the vehicle when the wheel locked or perhaps as a result of an inability to slow the vehicle. Rivian is still investigating the root cause of the brake failure. The only warnings received occurred after the event. I was presented with a Parking Brake Service Needed warning, and an indicator that no drive modes could be selected.