The contact owns a 2010 Toyota Prius. The contact stated that the brake failed to engage when he drove approximately 25 mph on rough road surfaces. The dealer stated that the ABS engaged and that was a normal brake function. The failure occurred several times intermittently. The Toyota manufacturer has not been contacted. The failure mileage was 46,000.

- Croton On Hudson, NY, USA

This is a complaint about a recurring event that has serious implications in the wrong situations. For five times now, since driving our new car, our brakes have released after going over a bump in the road. This bump can be as small as a crack caused by a nearby tree's roots, or larger like a pothole. It has also occurred when driving over slick sewer covers. It typically happens when braking, then hitting the bump, then brakes release, and the car is no longer breaking. This is especially dangerous in hilly cities like san francisco, where if this happens going downhill, the acceleration accompanied by the lack of braking going downhill can result in crashing into the next car, or worse, hitting a crossing pedestrian at a cross walk.

- San Francisco, CA, USA

My 2010 Toyota Prius brakes fail ( disengage or release) when braking on icy surface or while braking and a bump or pot hole is hit. I fist noticed this issue on Dec. 19, 2009 after a snow storm but it continues to happen even on dry road when a small bump is hit. I reported it to Toyota and they told me they could not find any issues with the brakes. Nothing was done to correct the problem. The car actually goes faster when you hit a bump while braking. The brakes release and it feels like you have no brakes at all for a few seconds. This is not right! it happens very unexpectedly and you can not judge your braking time correctly. It happened to me recently when stopping at stop sign before entering a cross road. I hit a patch of rough road and it drove me to stop passed the stop sign and was lucky there were no on coming traffic.

- Nesconset, NY, USA

The contact owns a 2010 Toyota Prius. While driving approximately 15 mph over a speed bump or pothole the vehicle accelerated for a few seconds while her foot was on the brake pedal. Although the surge lasts for a few seconds and occurred consistently she doesn't have control of the vehicle. The vehicle was taken to the dealer who stated that the accelerator pedal was operating normally. The failure mileage was 8,000.

- New Orleans, LA, USA

1. traffic came to a sudden stop so I hit the brakes. 2. vehicle hit a pothole while I was trying to stop and the brakes felt like they released. I had to hit the brakes again in order to gain control of the vehicle and bring the car to a stop. 3. I was told by the dealership that nothing could be done.

- Renton, WA, USA

There is an apparent momentary loss of braking ability that we have experienced several times. Going over a rise in the road, or bumps, and beginning a descent to an intersection, pressing the brake pedal seems to have no effect for about 500ms. This seems somewhat more pronounced when the road is wet, although possibly the explanation for this is we brake earlier in the descent as a precaution in less-than-ideal circumstances. We have made our local dealer aware of this at the 5K mile service appointment, and they acknowledged other complaints, and contact with Toyota. They report that Toyota is looking in to a fix. We are concerned about the ability to brake in an emergency situation with no safety margin. This seems reproducible.

- Brooklin, MA, USA

When I am braking and my car hits a pothole, it surges forward and the brakes do not work for a few seconds. This problem occurs every time I hit a pothole or bump in the road.

- Quakertown, PA, USA

At a right turn I encountered a pothole and applied the brakes. When my car actually hit the pothole I felt, for a very brief time, that the brakes didn't work and the engine rev up a little bit. I was driving at low speed. I could have hit the car in front of me.

- Snellville, GA, USA

I have a 2010 Prius purchased in September of 2009. It now has just over 5000 miles on it. Since the beginning, probably the first weekend I owned the car, when braking if I hit a bump in the road, uneven surface, or a pothole or something, the car often feels like it lurches forward and I have to immediately release and rebrake. The car feels out of control. I have very often felt like I narrowly missed lurching forward into the car in front of me. The Toyota dealership service department insists they only know of recalls regarding the sticking accelerator pedals, nothing about this braking issue. Yet I read plenty online about this problem, so I know it isn't only happening to me. What can you do"? I've listed all three types of brakes in the equipment area of this form, because I don't know what it is - something about the hybrid braking system also charging the engine" also I listed the date as the day after I bought the car but this is ongoing, not a single incident by any means.

- Fremont, CA, USA

1. events leading up to failure: Moderate braking (~0.2 - 0.4 G) at moderate speed (~20 mph) while driving over choppy pavement such as might exist where road work is being done. 2. failure: As the car passes over the choppy pavement, braking force declines sharply without a change in brake pedal pressure. The consequence of this is that the car stops farther down the road than expected despite reflexive increased brake pressure on my part. This has happened three times in 7500 miles of very moderate driving. So far I have not had a collision or other accident from this unexpected behavior. I have never experienced this behavior in any other car including dozens of rental cars. 3. what was done to correct the failure. Nothing. Tw*

- San Pedro, CA, USA

My 2010 Toyota Prius 1) lurches forward when braking while driving on an uneven surface, like a pothole, indent/crevice in road, etc. 2) the brakes repeatedly grab and cause the car to lurch when backing up on an uneven/slippery surface. Both problems seem to happen when applying pressure and braking at a slower speed. This problem has occurred multiple times (approximately 4-5) since purchasing the Prius in June 2009.

- Seabeck, WA, USA

The contact owns a 2010 Toyota Prius. Whenever the vehicle travels over a rough terrain at any speed the contact noticed that the brake pedal released causing the vehicle to suddenly accelerate. The braking distance and pressure applied to the brake pedal also increased in order to stop the vehicle. The dealer stated that the failure could not be reproduced. There were no prior warnings. The current and failure mileages were 8300.

- Chevy Chase, MD, USA

Loss of braking after hitting pot hole on freeway at low speed, less that 10 mph, similar to other incidences on this car.

- San Francisco, CA, USA

I have experienced at least three times in my 2 month old 2010 Toyota Prius a lurch forward when braking when my car drives over a bump, pothole, or something slick. Most recently I was driving downhill in dense traffic and the lurch felt like an acceleration. I had to slam on the brakes to avoid hitting the car in front of me. This braking problem clearly can be a hazard to safe driving and to any pedestrian or other close vehicle.

- Seattlew, WA, USA

2010 Prius. This has happened about 10 times now. Sometimes when I brake, I experience a sudden acceleration. It ranges from slight to a lurch. When it first happened, I thought it was something on the road and ignored it. When it was more pronounced and happened a couple of more times, I brought it to the dealer. They said they had no other reports and could not replicate it. The service manager took me on a test drive and the car was fine. I knew this would happen as the acceleration is only occasional. I was advised to call Toyota national, which I did, and was told that since this could not be replicated that there was nothing they could do and no recourse I had as the complaint could not be replicated. It has happened several times since, so I have paid close attention, as my heart has been racing, to the conditions. It has happened when I am braking while going over manholes, speed strips, cracks in the pavement. It feels like the tire is getting hung up slightly, doesn't get any traction.the brake malfunction light comes on. Also, on the multi-information display, the indicator has just moved from eco to chg.the other day, it was 34 degrees and I was braking as I came up to a light and the car slid and vibrated. I was going about 5 miles an hour. There may have been some black ice or frost on the ground, but the shaking was intense and I had difficulty controlling the car for a few seconds until I stopped.

- Washington, DC, USA

Yesterday, I once again experienced an issue that I have observed since I got my 2010 Prius in October 2009. There are two intersections close to my home that both are at the bottom of a hill and have potholes about 5 yards from the stop sign. In both locations, when my Prius hits the potholes, I have the sensation that the brakes release even though I am keeping pressure on them as I approach the stop sign. This does not happen with our 2007 rav4. I now know that I have to slow down as if the stop sign is before the pothole, but I worry about my wife driving it and about a condition that I won't be prepared for.

- Norwalk, CT, USA

Car: Prius 2010 (purchased in August 2009) problem: Braking failure on uneven surfaces or potholes I feel very unsafe and dangerous whenever I hit uneven surfaces or potholes because I feel I am losing control over my own car, especially since I am in los angeles where roads are not that great condition. I almost hit people several times because the brake and hit several cars when I was braking.... and, the brake is so weak that it doesn't hold the car that well on the hills. It goes backward whenever I stop at the traffic light on the hill and driving. I tried to talk to the dealer who helped me with purchase, but he made me look like I am a bad/unsafe driver who doesn't know how to drive well. The incident happened shortly after I purchased the vehicle, but I thought it was really my fault to not handling the "new" technology car well. It is very regretful to purchase a vehicle like this with so much money.

- Los Angeles, CA, USA

Many times while braking, when I hit a pothole or bump, the brakes go out, causing the car to accelerate. I feel a loss of control, which is regained a few seconds later. It's led to several terrifying situations where I've almost hit the vehicle in front of me.

- Los Angeles, CA, USA

There have been several times when the brakes of my 2010 Toyota Prius have released, often when I hit a bump or am going over a hill. The car feels as if it's suddenly accelerating even though I am pushing down on the brakes. This has happened at least 4 - 5 times per week since I bought my car in July 2009. Today, I was unable to stop as I approach an intersection despite pushing down on the brakes. The car hesitated and finally the brakes engaged. Luckily no one was coming through the intersection for if there had been, I surely would have hit them.

- Bath, ME, USA

When I am braking/slowing and turning and hit a curb or chunk of ice, or driving straight and hit a chunk of ice, my 2010 Prius brakes will completely go away. This has happened 4 times during the past 3 weeks of winter weather.

- Omaha, NE, USA