This is the 3rd time I have had a total lockout of braking on my 2010 Toyota Prius. This seems to happen most times if the road is slightly rough and downhill. Dealer denies any known problems but this last time I went completely through a stop sign. Had there been other traffic I would have had an accident.

- Woodhull, NY, USA

2010 Toyota Prius braking problems. Not always consistent braking pressure or braking force.

- Ogallala, NE, USA

I had trouble braking my 2010 Prius--when I hit the brakes and went over a bump at the same time the car sped up instead of stopping.

- Addison, TX, USA

I have a 2010 Prius that is now about six months old. I thought I was nuts when I described to my wife the incident of braking over a manhole cover and feeling the car seem to slip and jerk forward for a second. Seeing an article at cnn.com this morning caused me to write as this appears to be an issue.

- Dayton, OH, USA

I have a 2010 Toyota Prius iv. On at least two occasions, when I pressed the brake pedal and hit a pothole, the car's brakes seemed to have stopped working for 1-3 seconds. It felt as if I lifted my foot off the brake pedal but I was pressing it about 1/3 of the way down. This increased my braking distance substantially. Luckily there was no car or pedestrian in front of me. If there was one, I would have definitely hit them.

- Peekskill, NY, USA

2010 Toyota Prius (package iv) suddenly accelerates while braking over a bump, like a manhole cover. It occurs several times per week. No serious consequences so far, but could be troublesome if it occurs near other cars at a light or stop-and-go traffic. I took it to the Toyota Agency where they drove my car with me and did notice it, but didn't know what to do about it or think it was a serious problem. We also drove another 2010 Prius on their lot to determine that the same problem existed in it. I don't know if the braking is air, hydraulic, or electric, so I selected all three.

- Bethlehem, PA, USA

Infrequently, but repeatedly, while braking at low speeds, the brakes on my 2010 Toyota Prius will briefly cut out. When this occurs, the car will often seem to surge forward for the briefly period; it is hard to tell if this is simply a period of discontinued deceleration, or in fact a brief burst of acceleration. In over seven months of ownership, this has occurred at least 10 times, but certainly less than 50. It typically seems to happen when traveling on wet roads (I live in seattle) or after sudden change in the nature of the road (I.e. a pot hole or change of road surface height/type). So far this has not resulted in any injury or crash, but is concerning.

- Seattle, WA, USA

While driving over a small utility access cover in the road, at a relatively low speed, our 2010 Toyota Prius momentarily lost braking power and seemed to accelerate for a very brief moment. Although braking power was regained very quickly, this was alarming since there was a pedestrian in the crosswalk immediately in front of the vehicle. Although this has occurred only once at the time of this report, we have also experienced unusually sensitive braking while in reverse. This problem was alleviated by shifting into neutral and then again into reverse. The problem while in reverse has occurred twice at the time of this report. This is my 3rd Toyota Prius and the first with any braking issues. The car has less than 2500 miles on it now and had approximately 1500 at the time of the loss of braking power.

- Birmingham, AL, USA

1) driving at about 35 to 40 mph on a flat smooth road approaching a red light. Applying the brakes lightly to slow down before stopping. Hit a shallow pothole on right side. Probably a manhole cover. 2) very quickly, lasting only a split second, the brakes seemed to come loose and then re-engage. This didn't get my attention too much the first time, but then it happened a few weeks later again at the same place under the same conditions. It is apparently repeatable with my 2010 Prius! 3) nothing done yet. Does not seem to be severe enough to warrant worrying about right now.

- Lakeway, TX, USA

This has occurred several times in the 5 months that I have been driving my 2010 Toyota Prius hybrid. I would go over a pot hole or larger bump and instead of my brakes initiating when I press the brakes there is a quick acceleration and the car literally lurches forward instead of slowing down. Also, there is a long lag time between pressing the brakes and the brakes actually intiating which is consistent and occurs all the time.

- Seattle, WA, USA

My 2010 Toyota Prius does experience momentary brake failure when hitting bumps or potholes. The problem never lasts more than a moment and has not caused any accidents or near accidents. I have not brought the car for repair.

- Stamford, CT, USA

My wife and I purchased a 2010 Toyota Prius (new) in July, 2009. We have driven it slightly more than 8,000 miles. I have two safety related complaints to report with the braking system: Complaint #1 - several times (perhaps 10-15) when applying the brakes after coasting a short distance as I prepare to stop, I have momentarily lost all braking. It feels as if I have hit a patch of glare ice with all four wheels. It always happens the moment I first apply the brakes, and then after a moment (perhaps a second or less) the braking system returns to normal operation. For that brief time there is no braking action at all. Complaint #2 - several times (perhaps 8-10) when taking the car from "park" to "reverse" to back out of a parking space, the braking system is so sensitive that it is nearly impossible to control the car's speed. The brake pedal has nearly no "play" or "feel" to it, causing the car to jerk to a stop when the slightest pressure is applied. This results in a pattern of "coast a few feet and jerk to a stop, coast a few feet and jerk to a stop", repeated several times while backing up the necessary 30 +/- feet. I don't recall ever experiencing this problem while moving forward. Since I have experienced each of these malfunctions multiple times over these past seven months, the "approximate incident date" below is arbitrary.

- Berea, OH, USA

My wife and I have both experienced rare but scary braking in our new 2010 Prius. Under the right conditions there is a definite lag (less that two seconds)between application of the brake pedal and when the brakes actually engage. I suspect an electronic problem is not telling the electric traction motor to shut off fast enough during these braking events, so the car is braking against its traction motor which is still pushing the car. We've attempted to pinpoint the conditions when this unusual braking behavior occurs and here is our best description: 1. happens when one front wheel hits a slick spot like a wet manhole cover or storm grate during braking and the ABS cuts in 2. it happens during braking on very bumpy roads especially in tight corners where traction may be lost momentarily on braking causing the ABS system to cut in. 3. it happens at relatively low speeds below 25mpg and when the accelerator in not pressed and usually when the traction motor is running. We drive two other cars (non-hybrid)over the same roads in similar conditions and don't experience these braking anomalies. The Toyota dealer can't identify a problem.

- Martinsville, NJ, USA

I purchased a 2010 Prius in August 09 and have problems with the braking system. The car "lurches" forward when applying the brakes on a bumpy surface. I was fortunate on a number of occasions that there was distance between me and the car in front of me. After 3 or 4 occasions of experiencing this, I took the car to the dealership in Oct to have them check it out. I was told that the brakes were fine, nothing showed up in computer electronics and there were no recalls. They told me that I had to learn how to drive a hybrid and only drive on smooth surfaces! what city has smooth roads with no seams or bumpy surfaces on it. It continued to happen so I called the dealership a week later and was told that if I could recreate the problem the shop foreman would go out for a test drive with me. Recreating the problem is nearly impossible. I am a realtor and my livelihood depends on my having a reliable car. I am nervous driving my car and find that I drive always anticipating that I am going to have a brake problem...this is not a safe way to drive. The problem continues and I do not feel safe driving my vehicle. I am happy to hear that you are looking into it. Also, check out the Prius chat room for more complaints about the braking problem. Thanks so much for your investigative work.

- Washington, DC, USA

While braking and coming to a stop at an intersection, and if there is a bump on the road, the auto continues to move forward, even if you depress the brake completely, the auto continues to move forward, about another 10 to 15 feet. This has happen numerous of times and dealer says they have no answer to the problem.

- Burbank, CA, USA

We own a 2010 Prius and several times since we purchased it in November 2009 we have noticed issues with the braking system. On each occasion we were driving over an uneven or slippery surface (e.g., potholes, icy manhole covers) and when the brake was pressed it didn't immediately engage or catch. Rather, the brakes engaged after the car passed the slippery or bumpy surface. The problem seems to result in an acceleration (or perhaps slower deceleration) when one steps on the brake pedal. On at least one occasion, an indicator light on the dash display lit up.

- Washington, DC, USA

I purchased a Toyota Prius 2010 in October last year. I have had one braking failure incident when the car failed to brake as I was approaching a stop street. The brakes did not respond and then a few seconds later kicked in and the car came to a slow stop. I have also experienced about 6 incidents where my car accelerated while my foot was on the brake. These incidents occurred when I traveled over a bump or variance in the road. I have scheduled a service so that Toyota can review the braking system in my car.

- Forest Park , IL, USA

The contact owns a 2010 Toyota Prius. The contact stated his brakes are not holding when he steps on the brakes. The contact stated it feels as if he is braking on ice, sliding to make a stop. The failure is intermittent. The contact called the dealer and they stated they had not heard of this problem. The contact will be taking the vehicle in to be repaired.the failure mileage 6700.

- Woodbury, NY, USA

The contact owns a 2010 Toyota Prius. The contact stated that the brakes would not respond when she depressed the brake pedal. The failure occurred on an intermittent basis (a total of 6 times so far). There were no warning lights. She had neither taken the vehicle to the dealership nor called the manufacturer to-date. The vehicle had not been repaired at the time of the complaint. The vehicle identification number was not available at the time of the complaint. The current mileage was approximately 800. The failure mileage was approximately 60.

- West Bloomfield, MI, USA

Multiple events/failures, here is a summary: 1) while braking over rougher road conditions -- not potholes, but regular roughness/bumps in roads -- brakes feel like they momentarily no longer function/go out. As soon as you return to smooth road surfaces, the problem corrects itself. This has occurred on numerous occasions, the dealership with whom I purchased my vehicle were unaware of the problem when I called them, even thought it has been discussed in the national news. 2) brake malfunction on slippery roads. I was driving to work and going very slow, leaving more than enough space to stop from the car in front of me. I approached a red light and lightly applied the brakes. Having plenty of space to stop, I realized that my car was not slowing as it should. Regardless of the pressure applied there was no change. I ended up stopping by rearending the vehicle in front of me. The damage was minimal, but scary nonetheless.

- Blair, NE, USA