I had a 2008 Prius and live in Phoenix, Arizona, which is at about 1200 feet sea level. I travel to a town which is at 7300 feet sea level. When up in the altitude and when I step on the brakes, I hear a clicking or Ping. When I get back to Phoenix, it goes away. I talked to the local dealer in the mountians and he said he has had several people ask him about this. he asked the Toyota Tech experts and they cannot tell him why this is happening. I now have a 2012 Prius and the same thing happens. I cannot believe that Toyota has know about this for over 4 years and cannot explain why or have come up with a FIX. any body out there have any ideas??? Ron
I would think the only explanation for this is small air bubbles in the hydraulic brake system, These will expand at altitude. Ask the dealer in the mountains to bleed the brakes under warranty to see if it goes away. There have been reports of brake noise on PC caused by air in the system, usually described as chirping or barking.
