The Prius failed to stop when brakes were applied; instead the car did a lurch when the brakes were applied and then accelerated forward causing a 4 car collision; luckily no one was injured. Made Toyota aware of the problem, when they investigated they of course found nothing wrong with the vehicle's brake system.

- Skokie, IL, USA

The ABS braking system in this car is overly sensitive. This does not happen often, but it has happened enough over the past three years that I can clearly predict when it will happen again. If you are slowing down moderately say for a traffic light, on a dry road, but one that is in need of repaving (no pot holes, but just a rough surface), and if you are on a road that is going slightly downhill, the ABS braking system kicks in without a need. This causes your foot to sink briefly to the floor (on the brake pedal) and give the feeling of a loss of braking for a few seconds. The brake pads are fine (even with such high mileage, I still have over 70% of the original brake pads left). I have brought this to the attention of my Toyota dealer, who says everything is fine. The scenario described above might only happen once every few weeks, but both my wife and I have had this happen numerous times. I believe it is a software issue, perhaps related to overly sensitive sensors, perhaps in the rear of the car.

- Ambler, PA, USA

When I applied the brakes while going over a pothole or curb, the vehicle lurched forward. This has happened twice so far and I've only owned the car for a few months.

- Brooklyn, NY, USA

Numerous times when trying to stop, the vehicle would loss control of the braking when going over even the smallest of bumps. A few times even the traction control light would luminate when this happened. It also appeared that the vehicle would accelerate just slightly during this braking rather than slowing down. The best way to describe how the vehicle felt, is as if it was "hydroplaning", there was not control over the steering or braking. This happens every time the vehicle goes over any type of bumps, or potholes. I have children and this is definitely a concern. I have been told this is "normal", however I fear it is definitely a safety concern.

- Wilkes Barre, PA, USA

While pulling into a parking slot in a parking lot, which was on a slope, I applied the foot brake without any response whatsoever. The vehicle gained enough speed to jump the small stop-curb and hit a concrete wall next to it. The damage to the front of the car was just over $4000. I thought I had missed the pedal. On June 12th and 15th, I had two more incidents of the brake pedal going all the way to the floor while either at slow speed or stopped. My dealer says it was a problem on the 2010, but he has not seen it on a 2011. My wife now refuses to drive the car.

- Anacortes, WA, USA

The Prius brakes do not work well under certain conditions. When I slow down the vehicle and am over uneven pavement or a pothole, the car feels like it lurches forward for a split second. My reaction is one of panic and to press harder on the brakes. My wife and I have experienced this four times since we have owned the vehicle. We feel very unsure of the brakes and worry for bicyclists or pedestrians.

- Old Town, ME, USA

From the very start of my owner ship of a new Toyota Prius, the car started lunging when I would try to stop. It has continued to do so and I finally asked a friend who also has a Prius if she has that problem too and she does. I don't know what to do but I fear the safety of a car that lunges when you are trying to brake. Thank you for your time. Updated 11/24/2014

- Ann Arbor, MI, USA

The contact owns a 2011 Toyota Prius. The contact stated that while braking on an incline, an abnormal metal-on-metal noise was heard from the vehicle. The noise would become louder when there was only one occupant in the vehicle. The vehicle was taken to an authorized dealer fives times however, they were unable to duplicate or diagnose the problem. The manufacturer was notified of the defect. The approximate failure mileage was 25,456.

- Reston, VA, USA

When I am coming to stop at an intersection on a bumpy or uneven or snow covered road and apply the brakes the car lurches forward instead of stopping. I am lucky I haven't hit a car in front of me or a person crossing at the intersection. I have been reading the other complaints and they describe exactly what is happening with my car. I haven't yet tried to get this fixed, but I am starting today.

- Pittsburgh, PA, USA

The contact owns a 2011 Toyota Prius. The contact stated while driving approximately 20 mph on uneven road surfaces, the vehicle began to vibrate in a bouncing motion, when the brake pedal was depressed. The failure recurred four times. The vehicle had not been diagnosed or repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 25,000.

- Castanda , PA, USA

The brakes total disengage when applied on bumpy roads then work again after getting to a smooth surface. I reported this to the service manager at the new car owner meeting at Toyota and was told that I just have to get use to antilock brakes. I haven't gotten into an accident yet but I had several close calls almost hitting cars in front of me on bumpy roads. Has there been a recall for this problem?

- Oakhurst, NJ, USA

My car hesitates to stop or slow down when brakes are applied driving over a pothole, slick surface, metal road cover or a manhole. Instead of slowing/stopping, the car seems to eject forward. I took it to the dealership where I bought my car and drove with a service tech and he said in over 20 years of his experience, he's never seen this. I tried to explain that this car (and technology with regenerative braking) is only 3 years old, but he didn't seem to buy my complaint, nor were we able to reproduce this issue when I drove with a technician around the block. There are several online discussions regarding this particular issue : money.cnn.com/2010/02/04/autos/prius_timeline/"wpmp_switcher=mobile www.eetimes.com/author.asp"section_id=30&doc_id=1284377.

- Dallas, TX, USA

On two separate occasions in December of 2013, with two different drivers, the brakes on our 2011 model year Prius (purchased new in February 2012), failed to engage. The first time occurred when I was driving (with one of my teenagers in the car with me), and the second time occurred when my wife was driving the car alone. In both instance we pressed the brake pedal, but the brakes failed to respond at all. Although it is winter, the roads were clear, and the car did not slow down at all when the brakes were pressed / applied. Interestingly, after 30 - 60 seconds, the brake function restored itself. Since December the car has been at the shop at the Toyota dealership where we purchased the car. The shop has been unable to identify the source of the problem. Additionally, the shop indicated they contacted Toyota mechanics and service support staff to help identify and fix the problem, but Toyota claimed they never heard of such a problem or anything like it. Moreover, Toyota refuses to make any repairs or change any parts (even though the car is still under warranty). Yet, this past Wednesday (February 12, 2014), Toyota announced a recall on rav4's and other models for a software problem that causes the anti-brakes to intermittently turn off. This is particularly troubling, given Toyota's claim that they never heard of anything like this and did not know what to fix. Further, Toyota announced a recall on the Prius itself, for a software problem that might cause the car to turn off completely while driving. Clearly, Toyota has a problem with its software in a number of vehicles. At this point, all I have received is corporate double talk, and I urge the NHTSA to pursue this matter as vigorously as possible.

- Chicago, IL, USA

Car lurches forward when brakes are applied on bumpy or uneven surfaces, as well as slippery surfaces such as metal plates that you sometimes find covering city streets under construction. On ice, when applied forcefully, no braking action occurs whatsoever, even when pumped or release and reapplied. In Jan 2013, car slid more than 150' on a lightly snowy road into a ditch. My sense is anti-lock brakes are defective, but it could be some other computer override that kicks in. When stopping for a traffic light on a bumpy road, or over one of those construction plates, it's scary, and I feel lucky I haven't hit anyone.

- Davidsonville, MD, USA

My son was driving my Prius 2011 - I was in the passenger seat. We were sitting at a red light and he had his foot on the brake. Suddenly the car surged ahead although my son still had his foot on the brake. Immediately lights came up on the dash - brake, ABS? and picture of a car with skid marks. The brakes were then spongy, there sometimes and then not. I have it in the Toyota shop now and the repairs have been estimated to be $4,440. I did not buy the extended warranty. We met with the dealer and they were no help. I called Toyota and they offered me $1,500 after I pay the bill and told me it could take up to 8 weeks for me to receive payment.

- Park River, ND, USA

Love my Prius until I started to become scared daily by the unsafe driving conditions due to the car's tendency to lurch forward while braking over bumpy ground or potholes when coming to a stop or slowing down to turn. It's rather startling and fortunately has not caused an accident yet for no other car has been around when this happens. A different story with the other more serious issue with the braking system when needing to come to an immediate stop due to sudden stopping of the car in front. About a month ago, I experienced the "no brake" issue when suddenly needing to press hard on the brake for a stopped car in front of me. I had plenty of distance for stopping but because of the "no brake" issue had to steer off to the side to miss the car. Shocked and confused at what happened, thought maybe I did something wrong by not pumping the brake. Then two days ago, I was sitting at a red light when it turned green, traffic started moving but then suddenly stopped for an emergency vehicle to go through the interception. I pressed on the brake hard and just kept moving right into the rear of the truck in front. I now have about $1,800 of damages for the truck (no damage caused to it) had an hitch which punctured my bumper and bent the air condenser. I have decided not to fix it for it could happen again. When I decide what's my next safe car to purchase, I will have it fixed and trade it in for it as soon as possible for I'm now scared to drive it. The dealership reply to my concern is the same as with everyone else's complaint and review I have read, this is how the brake system works and no error. They do not want to take responsibility of this faulty brake system which creates unsafe driving conditions. Fortunately it was a truck in front of me this time. But what if it's a person walking across the road in front of me next time??

- Kettering, OH, USA

Was exiting the highway and was braking on the off ramp when I lost brakes and had to drive up on the bank. Upon releasing the brake pedal and re-engaging the brakes, I had brakes and came to a stop.

- Ashaway, RI, USA

Was at a complete stop at a red light with my foot on the brake pedal. While at the red light, the brake pedal went completely to the floor.

- Ashaway, RI, USA

In January 2012, I purchased a new 2011 Prius III because I commute roughly 90 miles per day between home and school. Thinking this was the optimal vehicle I didn't think twice when signing on the line. This was my first new vehicle, and to be honest I had heard nothing but great things about Toyota & thought I was going crazy when I started having issues with my brakes. Prior to owning this vehicle I own a Subaru impreza sport that we had traded due to poor maintenance from the dealership, who didn't know how to balance the AWD system & put a hole in my brake line. Being the my prior car had brake issues I denied the fact that my brand new car could have them as well. The issue is that anytime you hit ice, pot holes, gravel road, wet roads, bumpy roads etc, you lose control of the brakes. It feels as if they slip/accelerate and leave you in a moment of panic because it's not always a situation you can avoid. My car has been to the shop three times over the issue with a complaint on my braking system, and apparently this is a very known problem from Toyota. It took my dealership 3 complaints before they consulted their Prius tech, and basically printed off a paper with every complaint I listed above with no solution. They told us to call the Toyota care number, which has been a problem in itself. When my father spoke to the Toyota customer service on Wednesday they said they had to allow them three days to illicit a response to the complaint. Keep I'm mind that the three days falls onto a Saturday, and they therefore won't owe us a response until Monday, quite frankly they won't have a solution to this issue, and they will continue to let their consumers drive around with brake issues that have put not only me but others as well into numerous dangerous driving situations.

- Beckley, WV, USA

While driving at a slow speed, the traction control, brake and ABS failure lights came on. When I attempted to stop the vehicle, the brake pedal went to the floor without actuating the ABS system. I was unable to stop the vehicle using the service brakes. Since I was traveling at a low speed, I was able to slow down and come to a full stop using the parking brake. Now the vehicle is parked and undriveable. I contacted my local Toyota dealer requesting service and was told that they did not have a brake master cylinder or hydraulic brake booster in stock. I checked a second dealer and they told me that you can only get the two units together and that they were on national back order with no eta. Since purchase, I have experienced the issue that many people are reporting where the brakes release over rough road surfaces and the vehicle feels as if its accelerating. If you release and reapply the brakes it would stop. Like others, I dismissed this as a peculiar dynamic of the vehicle, however I am now convinced that there is a serious design flaw in this braking system which requires a deeper investigation. I have been in the auto industry for over 30 years and I can attest that it is not normal to have a total loss of your braking system like this, especially in a well maintained vehicle that is relatively new and have low mileage. This vehicle is now parked and available for your inspection if needed.

- Whitestone, NY, USA