Rear brakes gone with severe uneven wear at 55,000 miles

While in for an oil change, the tech pointed out that my rear brakes were almost metal to metal, and that one pad on each side of the car had severe uneven wear. He noted he had never seen rear brakes go this quickly in a Prius and he had never seen the uneven wear. He said part of the mechanism that allows the pad to slide in and out as the brakes are used had frozen, creating a pivot point, and creating the uneven wear. The front brakes are fine with plenty of meat left.

Parts were ordered, including new shims and other hardware to try to insure this does not happen again, and the brakes were replaced. I contacted Toyota Customer Care and basically got the old line that brakes are a wear and tear item but the issue would be sent onto engineers.

I am the sole driver of the car and use the regen brakes at every opportunity, which is most stops. Since long brake life is one of the benefits of regen brakes, this is disappointing to say the least. I have had to eat crow after touting long brake life as a Prius benefit to friends and family.

Has anyone else seen this uneven wear, or replaced the rear brakes sooner than this? I love the MPG performance of the car but this is the kind of stuff that will have me check out the competition when it comes time for the next car.

 

Thanks all for the replies and suggestions. There were not making any noise. There were no symptoms of a problem brewing. The car is 100% stock. Tire wear is perfect. I am nearing the end of life for these OEM tires and intend on replacing them before the Fall of 2013.

The tech was unable to find any explanation, other than the generic road salt explanation. Obviously all cars are designed with operating conditions in mind, be it road salt, extreme temperatures, etc. I suppose that while the brake components are designed to operate in harsh environments, I am the unlucky one out of x thousand that still has the slides lock up. I still find it odd that both sides had exactly the same problem. I forgot to note that after the roads dry up after salt has been used, I always run through the car wash with the under body wash to clean off as much of the salt as I can, in the hopes of helping the car last as long as possible.

I like the idea of having the brakes serviced annually, and will see what they charge for that. I also believe an aggressive stop from a higher speed while in neutral every month or two is not a bad idea.

 

Yes Bisco, I am very happy with the life I have gotten out of the original tires. I have been watching the tire threads here but not decided yet what to put on it.

My life time MPG has just dipped below the 50 mark, which it does each winter, and it recovers in the spring. The car has delivered on the MPGs as I have basically sat right around the 50 mark for the life of the car so far. My worst tank was around 42, which included hours of winter idling for heat, and my best was 58.something which was on a summer trip on almost exclusively 55 MPH highways.

I have wondered about a defect of some kind since it wore unevenly on both sides, but if it was a defect, I'd expect to see more stories like this on PC. It is unlikely to be a tiny piece of gravel that got stuck in the wrong place or a fluke since it happened consistently on both sides. As for the road salt being the cause, well, I am far from the first to drive a Prius in an area that uses road salt.

 

JD, do you have that TSB number handy? It is too late for warranty work but I'd like to read it and if it seems appropriate, let the folks at Toyota Care know about the possible relationship, as well as my local service manager.