While driving and braking on a bumpy road surface, the brakes will initially work, quit working momentarily, then reengage. This happens regularly. I just took it to the Toyota dealership, and they say the brakes are fine and there is no problem. There was a Toyota recall for this issue on 2010 models. I'm afraid this issue will cause an accident. How can I get Toyota to address the problem?

- Mahomet, IL, USA

The contact owns a 2011 Toyota Prius. While driving at various speeds, the vehicle hesitated to decelerate without warning. The contact stated that the brake pedal traveled to the floorboard. The contact stated that the brakes needed to be pumped in order to stop the vehicle. The vehicle was taken to the dealer where it was diagnosed that the brake cylinder assembly needed to be repaired. The vehicle was repaired. The manufacturer was made aware of the failure. The failure mileage was 59,000.

- Nevarre, FL, USA

I was moving forward in a turn lane on a city street preparing to make a left turn. A vehicle cut in front of my car and it was necessary to make a quick stop to avoid an accident. Immediately red warning lights lit up indicating a problem with the brakes. The repair statement from the dealer indicated that the brake booster with master cylinder assembly had failed and needed to be replaced. The repair required over two weeks to complete and I was informed that the procedure in the service manual for repairing the problem was incorrect.

- Charlotte, NC, USA

The contact owns a 2011 Toyota Prius. While attempting to park, the driver depressed the brake pedal and suddenly the vehicle accelerated forward and crashed into a pole. During the crash, the front end sustained significant damage. The air bags did not deploy. No injuries were reported and a police report was filed. The vehicle was destroyed. The manufacturer was not notified of the failure. The failure mileage was 21,000.

- Walnut Creek, CA, USA

On at least six occasions, I have lost control for a second or two while braking. While applying the brakes, and simultaneously crossing any sort of uneven terrain, the vehicle suddenly darted forward as I slowed. After reading a large number of similar incidents via a web search, I decided I needed to report this possibly dangerous issue.

- Evanston, IL, USA

While pressing the brake pedal in a bumpy road, I feel the car accelerates and try to jump and I usually press the brake hard to stop. I have been experiencing this several times but never report. To clarify more, it happens while pressing the brake.

- Hyayysville, MD, USA

There are 3 issues I am having with this Prius. The brakes are the first problem. As others have stated, I too have the same lurching forward when braking over bumby or rough roads. This has been ongoing over the last few years. Second, the suspension is creaking and crunching when making turns at low speeds under 20mph. This happens when the wheels are turned all the way right and all the way left. This crunching noise happens when backing out of the driveway, making U-turns, coming to a stop on an incline, and braking over speed bumps. I've had the dealer look at this for the last year when I come in for service and one tech says they can't figure it out, another tech says he hears it but can't find the root of the problem, the service mgr. Also went on a drive with me and reproduces the noise concern but the techs couldn't find it. Most were suggesting new front suspension components-struts, towers, links, etc. I replaced the two front struts and all of the extra components-the noise concern is still there. I am very upset about this. Third issue is the ice-motor. When stopped at a red light and the engine shuts off, the car lurches forward and makes a creaking sound. It's appears that something is not right. The engine seems like it is loose. The engine also makes rattling sound when cruising lightly at 15-25 mph with the accelerator pressed slightly. The sound is coming from the passenger side, under the dashboard-glove compartment area. This is a rattle sound coming from the engine. I've had this looked at as well and the dealer states they cannot duplicate it. I have recorded all sounds related to these concerns and am taking it back to the dealer this month.

- West Hollywood, CA, USA

Just want to add to the list of complaints about this car lunging forward when the brakes are applied, primarily when the car is driving over rough terrain but not always. It is always unexpected. I've had to change the way I drive, but I'm not always sure I could stop it in every circumstance. I've taken the car in to a Toyota service center twice to look at it. They either can't get it to happen while they have the car or they say it's normal. It's not normal for any car I've ever had in twenty plus years of driving. It has only gotten worse and more frequent over the course of the three years that I've had the car.

- River Ridge, LA, USA

Traction control and ABS warning lights came on. Cruise control stopped working. Took it to Toyota who said codes indicated failure of master cylinder. Cost of repair $3,400. I think they have a defective part problem.

- Santa Fe, NM, USA

The vehicle was parked in a typical supermarket parking lot during a normal sunny day. The vehicle starts normally as the brakes are depressed. After putting the car in reverse, the brake pedal pushed back as the vehicle starts to back up. The brake felt very stiff and would not depress until the foot is lifted and re-stepped on it. It has happened about a dozen times in the last 3.5 years, no specific place or time. Was not able to be duplicated at the dealerships. The dealer said it's safety feature when you step on the brakes too hard, it locks up as in a hand brake. However, the lockup I experienced is different and only happens occasionally during reverse where the brakes is not stopping the car from moving. Seems to occur more often on sloped surfaces than flat, but cannot duplicate as it happens randomly, usually with multiple passengers in the car. This can be a real safety hazard if some one is behind the vehicle.

- Temple City, CA, USA

My wife was driving our 2011 Prius during stop and go traffic. She said the car just took off on her on it's own she tried to brake but it wouldn't stop. It crashed into the motorhome that I was driving. The air bags never deployed. The car was totaled due to the extensive damage.

- Arlington, WA, USA

This has happened multiple times since I purchased this vehicle. The first time this happened was at 2,500 miles. While applying brakes on a rough road or when crossing a pot hole, cracked road, or bridge joint the brakes fail momentarily allowing the car to lurch forward. It his happens regardless of the speed. I could be traveling at 15 or 50 mph and the brakes will fail and lurch forward. I purchased the Prius new in 2011 and have told the service folks at Toyota about the problem and they look at the vehicle and are not able to find a reason for this brake failure. This is dangerous. I have to make sure I start braking a good distance from a car in front of me as I am afraid this defect will cause an accident. If I have to brake suddenly and am driving over any road that is not smooth my brakes fail and lurch forward. How many people need to get injured or die before Toyota fixes this defect?

- Madison, WI, USA

We have been experiencing braking abnormalities for 1-2 months, and when our brake malfunction light came on we had it checked out. Initially, about 1 month ago, the Toyota dealer's service dept. Could not detect an issue, so simply reset the computer. But, again, the malfunction light returned and again, we returned the car to the service dept. On this occasion, they told us that nitrogen gas has leaked from the accumulator into the braking system. Research indicates that this is a similar problem experienced by 2010 Prius owners. We would love for Toyota to fix this issue rather than us cover the $5000 for brake system replacement.

- Denver, CO, USA

While applying brakes on a rough road or when crossing a pot hole, cracked road, or bridge joint the brakes fail momentarily allowing the car to lurch forward. I purchased the Prius new in 2011 and have told the service folks at Toyota about the problem and they always tell me it?S normal for a Prius without noting anything in my file. I am here to tell you that the Prius brake design is faulty and the NHTSA should be investigating!

- Rio Rancho, NM, USA

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