Toyota (TM) has been hit with a lawsuit that claims several models of its cars have a brake defect. The class action lawsuit affects 2010 to 2015 Prius or Prius PHV, 2012 to 2015 Prius V, 2012 to 2014 Camry Hybrid, and 2013 to 2015 Avalon Hybrid vehicle owners.

In the suit, which was filed on Friday, owners of the Toyota cars contend that the braking system intermittently fails, increasing the risk of a crash, injury, or fatality. The alleged brake defect is said to occur in new or almost new vehicles, especially when driving on bumpy or slick surfaces such as potholes or ice.

According to the lawsuit, the brake defect stems from the brake booster pump assembly, which can fail to operate and ensure that the brakes engage when the brake pedal is depressed.

“Hundreds of thousands of Toyota vehicles are susceptible to this dangerous defect, and so far Toyota has refused to act responsibly to save lives and prevent injuries,” Steve Berman, managing partner of Hagens Berman, and attorney representing Toyota owners in the class action, said in a statement. “Crashes are happening because of this brake defect, and people are reporting injuries. Every day Toyota waits to respond is a day someone could suffer a fatality.”

Reports to the National Highway Traffic Safety Administration by drivers of the affected Toyota vehicles cited the braking issue, with one vehicle owner saying, “My brakes consistently lock and the car lunges forward...This caused a crash when the car was only a couple years old when the brakes failed to stop the vehicle and it lunged forward into the back of a car. This is extremely dangerous and I've seen this comment often with this vehicle. I don't understand why Toyota has not addressed this issue."

Another Toyota owner reported to the NHTSA, “Driving vehicle down highway, tapped brakes but brakes did not work, all the lights on my dash lit up. I lost traction in brakes causing vehicle to lose control."

The class action lawsuit is seeking both monetary reimbursement for anyone that has purchased or leased the affected Avalon, Camry, or Prius vehicles as well as a court action barring Toyota from continuing to sell the cars with the defective brake system.

Hagens Berman also represented Toyota owners in one of the largest automotive class action lawsuits in history related to sudden unintended acceleration of the vehicles. The case settled for $1.6 billion.

“This isn’t the first time we have caught Toyota in the crosshairs of a major safety defect,” Berman said. “As we did in the sudden unintended acceleration case, we intend to hold Toyota accountable for this serious hazard to Toyota owners and others on the road.”

Shares of Toyota stock were up 5.40% as of 2:09 p.m. EDT on Monday.