2022 Toyota 4Runner Brakes Problems

Brake failure. Unable to stop vehicle. Dealer found internal brake failure

Vehicle brakes normally initially at stop lights but then the brakes are unable to hold the vehicle stationary. Brake pedal slowly goes to the floor and vehicle creeps forward into traffic. No warning lights. No brake fluid leaks at wheels. Full brake fluid reservoir.

Driving home today, I felt that the brake was not performing properly. When I would stop at stop signs, slow down for traffic, or stop at red lights, the brake pedal felt spongey and the vehicle would not come to a complete stop. As I would step on the brake pedal, the vehicle would slow down, but continue to roll, while the pedal would continue to go farther and farther down until I could not press it any farther. When I made it home, I parked it in the garage, and even with the vehicle turned off, the brake pedal goes all the way to the floor.

Suddenly had difficult time stopping the vehicle without "pumping" the brakes. Brake pedal went to the floor, and car would not hold stopped. There were no warning lamps during the 400 miles of driving from western NY to Michigan for a Holiday with family. Had this happened as I was waiting in line on the downhill side of the Blue Water Bridge in Michigan, it would have been quite difficult to keep in line, not touching the car in front of us. We felt lucky to have discovered the problem while going to run an errand later. We saw no external leaks to the brake system (no fluid leaking) while trying to investigate what could be happening. The problem was reported to me as a leak in the brake master cylinder which was replaced under warranty at a Toyota dealer in Grand Blanc MI. It took two weeks to get the vehicle repaired (which presented other challenges to us to deal with, as we were only visiting Michigan at the time). The vehicle had 12,600 miles on it at the time that the brakes stopped holding.