The contact has 2010 Toyota Prius. The contact was engaging the brake pedal while driving 15 mph into a pot hole. Once the contact drove into the pot hole the brakes released and she was forced to pump the brakes in order to stop the vehicle. The contact stated that there was a loud screeching noise as well. The failure mileage was 600. The current mileage was 5,600. Updated 02/17/10

- New Market, MD, USA

The contact owns a 2010 Toyota Prius. The contact stated that while driving in the rain 10 mph over a bump in the road he lost the braking power and the vehicle surged. The dealer has not been contacted. The failure mileage was 2,800. Updated 02/19/10.

- Centerport, NY, USA

Toyota Prius 2010- car surged while braking to a halt. It felt as though I had suddenly lost braking power for a few moments, like I had hit an ice patch. But the road surface was dry. This was the second time it happened to me, the first about a week or 10 days ago. Car was purchased on 1/4, delivered on 1/8/2010. The problem is not reproducible, but both times the car was moving at relatively low speed (10 mph or less).

- Washington, DC, USA

I knew something was wrong, even before reading the online complaints about the 2010 Prius and its braking problems that echoed my suspicions---- when sometimes braking over a pothole or railroad tracks or ice or any kind of bump, there is a surge of acceleration. To the extent that one time my 15 year old daughter said, 'what was that?" I'd driven a Saab 93 for 130,000 miles before we recently bought the Prius--I never felt anything like this before.

- Haworth, NJ, USA

The contact owns a 2010 Toyota Prius. While driving 45 mph and attempting to engage the brake pedal it extended to the floor; however, within a few seconds the brake would respond. She experienced the brake failure three times; during the second failure the brakes didn't respond and she collided into a vehicle and injured her neck. She has not taken the vehicle to the dealer since the failure occurred only when she hit a bump in the road. She will take the vehicle to the dealer to be diagnosed. The VIN was not available. The failure mileage was 3,000 and the current mileage was 10,000. Updated 03/09/10. The consumer stated she experienced brake problems with her vehicle twice while slowing down to come to a stop or to make a turn. The consumer stated she felt a release of the brakes and a surge after hitting a pot hole in the road. Two ago, while driving, she hit a bump in the road and she felt the same acceleration, like the gas pedal was applied, but she was braking at the time. The consumer was involved in an accident where she was rear-ended. She was at a stop with her foot on the brake. The consumer stated when she was hit, she was pushed forward and hit the vehicle in front of her. Updated 05/13/10

- Chandler , AZ, USA

When my vehicle is first started in the morning the brakes grab suddenly. This occurs at least twice a week. I have owned the new car for 1.5 months. I have not taken the vehicle to the dealer.

- Mesa, AZ, USA

My 2010 Toyota Prius lurches forward when braking when I hit an uneven surface, like a pothole, indent/crevice in road, or other type of uneven surface. There is a loss of braking for approximately 1 second and you instinctively hit the brake again to regain braking. It is as if the car accelerates for a split second and you lose control before you hit the brake pedal again. It seems to happen when I am braking at a slower speed and coming to a stop. This problem has occurred multiple times (approximately 12) since I purchased and received my Prius in September 2009. No accidents have occurred thus far because of this problem., but I am very concerned about this problem and my/others safety. I reported this problem to the Toyota dealership I purchased my car from in October 2009. They performed a health check on the car to make sure everything was operating fine and reported that it was, and told me to bring the car back in if the problem continued. I went into the dealership to talk to someone on 1/13/10 to again discuss the problem. The dealership representative said they he is aware of reports of the problem and will get back to me with any new information.

- Proctorville, OH, USA

The contact owns a 2010 Toyota Prius. While driving approximately 45 mph and applying the brake pedal, the vehicle would not respond. She felt the vehicle accelerating while attempting to brake. On one occasion, while depressing the brake pedal on a hill, the vehicle accelerated down the hill. This occurred on several occasions. The dealer was contacted and advised bringing the vehicle in for a diagnostic test. No repairs were made to date. The current and failure mileages were under 67,000. Updated 04/01/10 the consumer stated when she applied the brake, it didn't engage and the vehicle momentarily surged forward before the brake finally engaged. Updated 07/06/10.

- Mt. Kisco, NY, USA

Braking irregularity on icy surfaces, vehicle feels like rear wheels skid 4-8 feet then all wheels grab when normal braking for a stop sign. Enough deceleration to have seatbelt grab and dog projected into front seat area from rear cargo platform. Same feeling as if brakes were locked up while moving on solid ice and the surface changed to dry road.

- Hugo, MN, USA

There appears to be a problem with the brakes on my 2010 Prius. There is a sudden loss of braking force if I apply the brakes while rolling over uneven pavement. When it first occurred, it was on snow. Once I sailed into the intersection. The second time, I almost rear ended the car in front of me. I went home and then drove my wife's Acura in the same snowy conditions at the same intersections and didn't experience any problems. I know the problem wasn't due to weather conditions. I have since then been able to reproduce it in dry conditions. The common condition is braking over uneven surfaces. Some people have said that it feels like sudden surge of acceleration. The gasoline engine isn't (usually) on while the car is braking. The surge isn't due to the electric motor malfunctioning because on smooth surfaces, it behaves as expected. I believe what they feel is a loss of braking power which makes the car feel like it is accelerating. Some people have been told that this is normal ABS behavior. I've owned several cars with ABS and this is not the same nor what I would consider 'normal' behavior. It could be a combination of the uneven surface with ABS, regenerative brakes, friction brakes, suspension spring rate and tires. While normal ABS will exhibit less braking force and longer distances to stop when it is engaged, it isn't the same as this condition. Or at least it shouldn't be this touchy to engage. When it happens, it is rather alarming. I really like this car. I think it is a great piece of automotive technology. However this needs to be addressed. I can't accept it being a normal quirk of the car. I travel with my wife and young kids in this car. If I can't be made to feel safe in the car, I will be trading it in sooner than expected.

- Westampton, NJ, USA

Brakes temporarily disengage during braking if can hits a bump or pothole in the road. It is only a momentary instances before the brakes re-engage, but it gives the feeling of accelerating. It has happend to me about a half dozen times since purchasing the car (2010 Toyota Prius) in August 2009. Luckily no cars or pedestrians were in front of me when this problem occurred.

- Manalapan, NJ, USA

I have noticed the brakes in our 2010 Prius are not as effective as slowing the car as they were in our 2004 Prius. On January 3 I was exiting the highway. As I was about to leave the highway while braking I encountered a slight bump in the pavement. I noticed that when this occurred the braking effectiveness dropped substantially, to the point where the car felt as though there were no brakes being applied. As soon as the bump was gone the braking effectiveness returned.

- Amherst, NH, USA

2010 Prius acceleration surge - when I drive over a sewer cover or any similar indentations in the roadway the vehicle surges forward in an aggressive manner. I need to apply the brakes or steer to avoid any object in the path of the vehicle. It is very unsettling and dangerous since the surge is strong and unpredictable.

- Chicago, IL, USA

Our 2010 Prius unexpectedly lurches when braking. This occurs when it hits a pot hole or when the surface is slick / slippery. It does it every time a certain pothole is hit - that is, we can reproduce the lurching. This lurching, which feels like an unexpected acceleration, significantly and unexpectedly increases the stopping distance. This has almost resulted in the Prius striking the car in front of it. It makes it impossible to safely judge your braking distance in order to come to a safe stop because you never know when this phenomenon will occur. This also puts pedestrians in the cross walk at risk, since the ability to stop accurately is affected. We have taken the car to the dealer twice. They are able to reproduce the phenomena. However, they say that the car tests out "within specifications", that there is nothing wrong with the vehicle, that it is just the way it is made, and that we just have to get used to it. They say there is nothing to fix or repair. They took another 2010 Prius off of their lot and ran it over the same pot hole and it had the same problem. An article by paul a. eisenstein, msnbc.com contributor, updated 7:29 a.M. et, tues., Dec. 29, 2009 describes exactly the problem we are having, and it seems to be related to the braking system. This does not seem to be a problem with only my vehicle - it appears to be a fleet-wide problem. Having the brakes cut out unexpectedly is a major safety concern. We do not feel safe driving the vehicle.

- Commerce Twp, MI, USA

I am writing in response to an article I read on msnbc.com where people mention a problem of which I have experienced the same thing. I have owned a 2010 Toyota Prius for 2 months/5,000 miles. On numerous occasions, I can feel the brakes slip. To be more exact, it feels as though, when I apply the brakes, the car lurches forward and then begins braking. There is a specific situation near my house where this consistently happens. It is when I am coming down a steep hill, and I apply the brakes to prepare for a right turn, the car performs as I mentioned before. It lurches, and then begins braking.

- Jamaica Plain, MA, USA

Once, when transitioned from smooth to uneven surfaces during a parking operation on uneven, downhill pavement, I experienced a lack of brake pedal pressure. I do not recall any change of acceleration, simply the loss of brake pedal pressure for a very brief time, perhaps for a second. It surprised and shocked me to a fair degree as I thought, at the time, that my brakes had failed. By pressing harder the brake pedal pressure returned and I was able to stop the car normally. I now take into consideration the pavement surface condition when applying my brakes as I feel the car's braking system is peculiarly sensitive to uneven pavement surfaces.

- Guerneville, CA, USA

I have a 2010 Toyota Prius. While driving behind a car on 17th street in manhattan the car in front braked coming to a light I in turn hit the brakes and hit a pot hole at the same time, the car's brakes seemed to jump or release and I had to push down in a panic to try and control the car, I missed slamming into the car in front by inches.

- Point Lookout, NY, USA

In my 2010 Toyota Prius, as I'm braking on a rough surface, it feels as though the car accelerates for a split second. It happened most recently on 12/22 as I was coming to a stoplight on a road with patches of snow/ice debris in cambridge, MA. It has occurred maybe 5 times since I bought the car in August, and at first I thought I was just imagining it. When it happens, my heart races and I press the brake harder, which seems to make it engage. The end result is that the stopping distance is longer than it should be, and it's definitely scary. I took the car into the dealership on Wednesday, December 23rd to have it checked out. The car was approved as functioning as normal, with a write-up saying the master mechanic looked at it, took it for a drive on a bumpy surface, and cleared it as fine. The client services manager explained that I just needed to get used to the sensation when the ABS kicks in.

- Cambridge, MA, USA

Something weird happens when I am braking. As I am slowing and braking evenly, there is a very brief surge like I hit the accelerator, but my foot is no where near the accelerator. It feels like the brakes are not working at all for a brief moment. It seems to happen when I hit a bump, but it can also happen for no apparent reason. It has happened about 5 times now and it seems to be increasing in frequency. It also happened once when my boyfriend was driving it.

- Petaluma, CA, USA

Car hit bump or pothole on the freeway, while braking, braking power was significantly reduce for a short period of time.

- San Francisco, CA, USA