The contact owns a 2010 Toyota Prius. The contact stated the brakes failed to engage while driving 55 mph on an exit ramp. The vehicle eventually stopped by depressing the brake pedal with force. The vehicle was driven to the dealer for diagnostic testing which confirmed that the brake power booster pump was leaking internally. The manufacturer advised that the vehicle was not included in the NHTSA recall campaign number 13V235000 (service brakes). The vehicle was not repaired. The failure and current mileage was 46,000.

- Mystic , CT, USA

When hitting larger size potholes or bumps in the road I lose control of what feels like the rear end, its as if the vehicle brakes gives way when the rear tires hit the object, car shimmies slightly, the brakes stop working for at least 3 seconds as the car lurches forward. The brake also depresses further to the floor while it happens. There's a particular spot on my way to work that continues to cause the problem. Its heading down a small declining hill before a turn to the left. If I were to tailgate someone and have that happen I would surely hit them because there's no control of the vehicle for a few seconds after hitting the object. This object goes straight across the 2 lanes as if the concrete paving was poured too high in a long horizontal line. I think it has to be above a 4-5 inches or so because I'll hit smaller ones and I'm fine and I've tested it on different objects, its higher raised items causing the behavior. It happens when its dry, wet or icy out, but you have to be applying the brake to really feel it as far as I can tell. My passenger also felt the loss in control each time this has happened and its been numerous since owning the vehicle.

- Attleboro, MA, USA

For the entire time that I've owned the 2010 Prius, the car lurches ahead virtually every time I run over a pothole with the brakes applied (I.e., approaching a stop sign). When I mentioned this at one of my first appointments, I was assured there was nothing wrong. Now the problem continues and I've been reading that many other people have the same issue.

- Des Moines, IA, USA

I have previously (2010 or 2011) filed a detailed report of the consistent anomaly that occurs while braking on a rough surface or upon hitting a pothole, manhole cover, etc. In this situation, the feedback from the vehicle suggests that the brakes have disengaged. Based upon 2+ years of additional experience, I would note that: (1) this anomaly occurs consistently, and it has not disappeared or attenuated, (2) I believe that stopping distances are longer than would be expected without this anomaly, (3) my Prius was manufactured after the 2010 software fix, and (4) other drivers of 2010 and later Prius cars have reported the same phenomenon when I asked about it (see below). Most importantly, I would note the following source of evidence which you might easily pursue further. I have been living in New York city (nyc) for most of the last two years. The nyc taxi fleet includes a sizable number of Toyota Prius cars. Every time I take a Prius taxi, I ask the driver if he has encountered a similar problem when braking on rough surfaces. In more than a dozen such instances, drivers have consistently reported this same problem. While you may not want to trust my evidence on this matter, it would be very cheap for NHTSA to send an investigator to some of the large taxi garages in nyc to interview drivers with experience driving Prius taxi cabs. Given the large number of miles logged by taxi drivers, this could be an important source of information from highly experienced drivers --- who must regularly contend with nyc's myriad potholes. I would finally note that --- other than this anomaly --- I love my Prius. It is a great car. I would just like for Toyota to figure our what is causing this anomaly and fix it.

- New York, NY, USA

The contact owns a 2010 Toyota Prius. The contact stated that while driving 30 mph, the brake and traction control warning lights illuminated. The vehicle became difficult to stop when the brakes were applied. The vehicle was towed to the dealer for diagnosis and the contact was informed that the brake booster pump assembly would need to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The failure mileage was 39,001 and the current mileage was unknown.

- Chula Vista, CA, USA

I'm a owner of a 2010 Toyota Prius. I almost crash into another car, due to the brake system of this vehicle. I had to drive off the road pavement to avoid the car accident. I had multiple times near miss car accidents before reporting this issue. Due to the very poor braking system on this vehicle. The brake response is very poor. In a quick reaction for braking, this car's brakes will not stop in time to avoid accident. After a recent close car accident 6/3/2013, I have to give a lot of distance between my car and other cars for braking in time to avoid a car accident. As a buyer purchasing a new car, the braking system is a number one priority for safety for a family owned car. I purchase this car for a fuel gas saving car, but it's scary driving this vehicle. Due to very poor brake system in this 2010 Toyota Prius. Toyota company needs to recall the braking systems for all 2010 Toyota Prius. It's needs to be checked and fix for better braking quality. I want to sell my 2010 Toyota Prius, due to this issue of braking, but I can't sell this car due to I still have to pay off my auto loan. My family fears for my safety and other Toyota Prius owners out there. Please someone look into this matter. I fear for my family's safety due to this problem. [xxx] information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Visalia, CA, USA

The contact owns a 2010 Toyota Prius. The contact stated that while driving 35 mph, the contact applied the brakes then the pedal went to the floor and the vehicle failed to stop. The contact pumped the pedal and eventually the vehicle stopped. The vehicle was taken to a dealer where the contact was informed that the brakes needed to be replaced. Several days later the failure recurred. The vehicle was returned to the dealer and the contact was informed that the master cylinder and the brake booster would need to be replaced. The vehicle was repaired. The manufacturer had not been notified of the failure. The failure and current mileage was 144,000.

- Columbiana, OH, USA

The vehicle has a nasty habit of losing brake pressure over bumps. This can be duplicated easily and is a known issue that Toyota has yet to rectify. Simply drive over a bump such as a break in concrete on a bridge, pothole, etc. And hold on tight. This can result in a crash and serious injury as occupants experience a sudden loss of braking force which can induce panic and collision.

- St. Charles, MO, USA

In the past (starting at 2,800 miles) and reported numerous times to the dealer (huntington Toyota), Toyota corporate and the NHTSA, whenever the car went over a rough road service while braking at about 10 miles an hour the regenerative braking would cut out and give the sensation of the car surging forward requiring much greater braking effort to bring the car to a stop. The brakes would reset after a full stop and they would act normally until the next time braking was done on a rough road surface. Toyota claimed that this was normal behavior for the Prius ABS system, even after the firmware upgrade was applied. This time the brakes did not reset after a full stop and every warning light on the dashboard lit up. There was no regenerative braking available. The car was brought to the dealer who has had it for more than a week, and is replacing major brake system components under my extended warranty. I was told that without the warranty these repairs would have cost me over $4500. This has been an ongoing and dangerous situation, which may be finally resolved after all of the brake component replacements. As an aside, the brake pads show significant and unusual wear because the regenerative braking did not work as it should.

- Centerport, NY, USA

Brakes failed while driving. Pedal went to the floor. Very little braking power left. Luckily I didn't have to stop suddenly and was able to bring the car to a stop slowly. Had the car towed to Toyota dealer where they diagnosed the problem as the brake booster / master cylinder. They told me there was air in the brake system. I received a quote for almost $2900 to fix the brakes. I called Toyota corporate office and asked for assistance with this catastrophic brake failure but was refused. Searching online found others with same failure. In particular, there was a person with 43K miles with exact same issue, and Toyota refused to help him. This is a very dangerous failure and should be a recall. Please investigate fully and feel free to contact me for any assistance. I am in the process of replacing the brake booster but I will keep the old one in case you need it for your investigation. I had similar issue on my 2004 Lexus RX330 and there was eventually a recall for it. It is unacceptable for a 3 year old car to have this kind of a safety failure. My wife and kids could have been seriously hurt or killed.

- Valencia, CA, USA

First incident: April 15, 2013 I lost my brakes while I was driving home from my night shift work as a registered nurse. I was at an intersection two blocks from my house when I felt the brake was failing. It was a good thing that I was driving slow to make a turn when I felt the brake system was not working. I was able to steer it to a parking lot nearby by using the foot brake. Prior to this incident, I heard squeaking noises for about three days whenever I step on the brakes. I was relieved that I did not get into an accident. Action after the 1st incident: April 24, 2010. We towed the car to dch Toyota freehold, and it took about 5 days to repair the brakes so they gave us a loaner car which we truly appreciate. But when we picked up the car, the brakes were fixed but the squeaking noise is still present, and our windshield was cracked. We called the dealership right away to inform them about the squeaking noise and to complain about the cracked windshield. I was told by the service representative that their technicians tested my car and deemed it safe to drive and that they would never release my car unless they know it is safe to be on the road. Second incident: April 29, 2013, I lost the brakes again while I was on my way to work around 7:00 pm. I really got very scared because there was so much traffic at that time. I was able to stop and park my car slowly to the curb without hitting anybody else by using the foot break. Action after the second incident: Same night, we towed the car back to the dealership for repair, and after a week of waiting, they finally came back to us specifying that the whole master cylinder and brake pad assembly is defective and needs to be replaced and will cost more than 4K for parts alone. Contacted Toyota about this issue, and they said that they will not assist us, since we exceeded the warranty period.

- Monroe, NJ, USA

On 01 May 2013, I was driving my two daughters home from school and the brakes on my 2010 Toyota Prius failed. The brake pedal became very stiff and the brakes did not respond. I began to panic because we were traveling down a steep hill. I continued to pump the brakes and suddenly, the pedal gave way and the car came to a screeching halt. I was luckily within walking distance of my house. I had my car towed to the dealership and they informed me that my brake booster and master cylinder needed replacement at a cost of $5500. I'm shocked. My car is 3 years old. After research, I discovered this is a common problem for the 2010 Prius. What I find most disturbing is this is clearly a manufacturer's defect, that is an extremely dangerous safety hazard. Prior to owning my Prius, I was a loyal Toyota buyer. I have had consistent acceleration issues with my brakes, even after the recall. If Toyota does not address this issue, I don't intend to purchase another Toyota product.

- Kapolei, HI, USA

While I was braking to stop at the red light, the car accelerated. I moved the steering wheel to hit the curb to prevent crossing the red light. It happened to me couple of times. Then I realize it happens only when I am driving over uneven surface or over bumps. It is really scary. I almost hit a car seattle downtown going down the hit because my car accelerated instead of stopping. I took it the car dealer but they said there is no problem. I am afraid that I might get in a big accident.

- Renton, WA, USA

Vehicle surges when brakes are applied while traveling over railroad tracks or rough pavement. Surge lasts for 1 to 2 seconds until braking resumes. Vehicle behavior can be easily replicated.

- Dallas, TX, USA

The brake booster pump began running continuously when the vehicle was on. Warning lights on the dash indicated brake failure and anti-lock system failure. After I took the vehicle to a Toyota dealer, they determined that the brake master cylinder/anti-lock assembly had failed. The repair took two weeks and cost $3000.

- Burien, WA, USA

I was driving to work this morning and a man stepped off the curb right in front of me (not in a crosswalk). I hit my brakes, and hit a pothole in the road at the same time. The car accelerated and felt as if it was shuddering, it was not braking at all even though I mashed the pedal to the floor. I was forced to swerve to miss the man, which I thankfully did. After that I got moving again I applied the brakes and they worked fine. When I arrived at work I tried it again by finding some potholes in the parking lot. @ 15 mph the problem occurred again only when I was hitting the potholes while applying the brakes. I went to Toyota.com and found this has been an issue since Feb 2010. I purchased my car in Nov 2010; I then called my service dealer and talked to the service manager who claimed to have never heard of that problem even though I told him I found the info at the pressroom.Toyota.com website. He then proceeded to let me know I should not believe everything I read in the internet and offered to let me bring it in and he will look at it. I am leaving work early today to have it looked at.

- Gloucester, VA, USA

Multiplie incidents: We will be driving the vehicle and hit a bump / pot hole and be braking, but the car will accelerate.

- Plymouth, MN, USA

In the morning I started my car and the ABS light and warning lights came on and started beeping. I reversed my car slightly to check the brakes and noticed my brakes were not being responsive. I put the vehicle into park and called the wondries Toyota dealership and told them my brakes were not functioning properly and my ABS warning light was on. Despite my having informed them of my brake failure, they told me to bring the car into the dealership. I reversed out of my garage, shifted the car into drive, and proceeded down the hill with caution. I did not press on the accelerator. My car began to accelerate down the hill due to gravity and reached a speed of approximately 15 mph, at which time I pumped the brake pedal but the car would not stop or slow down, and it continued moving down the hill. At the bottom of the hill, after traveling approximately 1/4 of a mile, I turned right into a small street with a slight incline in order to stop the momentum. My car slowed and I put on the emergency brake and put the car into park. I called my brother for help. When he arrived, I turned the car on to show him the flashing ABS warning. It flashed for about another 15 seconds before suddenly stopping. My brakes then began functioning again though they felt spongy when I pressed down on it. I turned on my emergency lights and drove slowly to the dealership. I parked the car and turned off the engine. When a representative came by, I turned on the car and she pressed down on the brake to feel them. The ABS lights suddenly came on again and she said the brake pressure did not feel right and there was something definitely wrong with my brakes. After it was assessed I was informed I needed a new ABS actuator assembly and an accumulator pump for the master cylinder. Total cost was estimated as $4600.

- South Pasadena, CA, USA

I was driving my 2010 Prius in a congested area and cars in front of me stopped suddenly. As I braked hard, the car seemed to lurch forward for about one second, maybe longer, and then the brakes kicked in. I noticed that the road was rough. The surface was dry. Fortunately, I had allowed ample distance from the car in front of me, and there was no collision, but it was very unsettling. In the previous month, I had three or four less intense sensations of "lurching forward, " which occurred when I stopped at a particular intersection when I had just started the car, but the road was smooth.

- Ardmore, PA, USA

I had been hearing a lot of grinding noises that just got worse. When I went to the dealer, they discovered that my brake pads had failed/frozen. They replaced my pads and machined my rotors. They could not explain why a car I had for only a little over a year had this problem. They at first blamed my driving, and then the roads (I.e. too many gravel roads). Now, at 68,300 miles those pads have now failed again. One is completely worn down and the rotor is now rusted through. No one can explain why this is happening. When I demanded an answer, they told me that a "bulletin" had gone out to the dealers only stating that due to the pads failing, they were "redesigning" them. But, they would only replace for free those that fell under the 36,000 mile warranty. I don't understand why, in less than 69,000 miles I have had to have this repair done not once, but twice. They tell me no other owner has had this problem, but I find that hard to believe. Can anyone tell me if there are other complaints of this type, and what can be done to rectify this problem.

- Howe, IN, USA