On uneven road surfaces (washboard road, many small potholes, gravel roads, rough road shoulders) brakes would give out if braking hard. If felt like once ABS kicked in the brakes would get almost completely released. The car would brake just fine on flat surfaces, wet or dry. I have multiple vehicles and know how ABS brakes work but thought the Prius brakes were just a bit more sensitive and I have to watch my distances more carefully and avoid hard stops. Then on April 23, 2018 the car started to make some strange noise but no dashboard lights came on. I continued driving and noticed the brakes were working only intermittently. After I almost crashed when attempting to break in traffic I limped back home and took the car to the dealership. The repairs to replace brake pump and cylinder assemblies cost $4,193.31 but the car was driveable again. However, I noticed that the repairs also corrected the ABS problem that was present since the car was new. I think anyone who drives a 2011+ Prius should get their brakes checked for emergency braking where brakes stop working thus allowing the car plow ahead even if the brake pedal is down to the floor.

- Fort Lauderdale, FL, USA

The brakes temporarily disengaged sometimes when braking. At around 100,000 miles, the brake accumulator would constantly make noises while driving and after shutting the car off. Eventually the brake accumulator and brake booster failed completely at 117,000 miles, costing around $4,000 to repair.

- Irvine, CA, USA

The ABS/brake/skid/warning triangle on. My 2011 Prius III is 121K mile. This went on/off for a few days then it was on the whole time. The brake seems to loose the hydraulic power brake. I feel like the brakes feel weird whenever hit small bump, brake just failed for a second. I went to Toyota dealership they said it's the actuator that need to be replaced and it's expensive $2-3K. They said it need to be fix soon because brake might fail at any time. There seems to be a warranty enhancement for the 2010 and older but not 2011 and newer. Seems like Toyota still have the same issue with newer model, not fixed yet. Please bring this issue up for safety reason.

- Baton Rouge, LA, USA

Unknown cause. The breaks temporarily disengage (for anywhere between 1-3 seconds) when the car encounters a small bump or pot-hole in the road, while breaking downhill. Usually happens when breaking hard on a declined freeway off-ramp. This has almost caused me to rear-end another vehicle on multiple occasions.

- North Hollywood, CA, USA

The brakes are pumping slow speeds and the vehicle makes much more noise. The car makes buzzing sound every 30 seconds or sooner. A repair person said it is the ABS actuator that is about to fail.

- Austin, TX, USA

While driving on the highway, without warning, I lost power assisted breaking ability - accompanied by a number of dashboard warning lights. I was able to safely stop the vehicle using manual breaking. I had the code checked and have learned that the (code 1391) brake accumulator failure is a common issue in the Prius and has been subject to a recall/replacement for the years prior to my make (I believe 2008-2010). Clearly this is still an issue and the sudden/no-warning failure of the system causes an alarming and potentially dangerous loss of breaking control during high speed driving. Luckily, I was not using the breaks at the time of the failure and was able to determine that the manual break pads were serviceable but I needed to rapidly increase the pressure on my breaks to slow down sufficiently to avoid an accident.

- Spartanburg, SC, USA

My brakes consistently lock and the car lunges forward when I hit a pothole while braking. This caused a crash when the car was only a couple years old when the brakes failed to stop the vehicle and it lunged forward into the back of a car. This is extremely dangerous and I've seen this comment often with this vehicle. I don't understand why Toyota has not addressed this issue.

- Wayne, NJ, USA

The contact owns a 2011 Toyota Prius. While driving various low speeds, the ABS and traction indicators illuminated without warning. In addition, when the brake pedal was depressed, the vehicle lunged forward. The dealer (universal Toyota in san antonio, Texas) diagnosed that the brake booster and the pump for the booster/accumulator were faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and provided the contact with case number: 180-4162-158. The failure mileage was 98,000.

- Converse, TX, USA

I was getting on the interstate and all of a sudden I lost power and my dash lite up check hybrid system /ABS/ breaks. I can not drive my car because it has no power please help thank you

- Eureka, SD, USA

I was driving at about 35 mph and all of a sudden my brakes stopped working. The brake, ABS and traction lights came on all at once. I somehow made it home but I could have easily crashed. I had my 9 year old in the back seat and he also got very scared. Now I cannot drive my car and the brakes feel as they as stuck and very hard. I took my car to a reputable mechanic and he told me it is giving him code C1391. This is the same problem that the 2010 Prius had under the recall. My Prius is 2011 and not under the recall. I feel that the 2011 should be under recall because many thousands of lives are in danger now.

- Houston, TX, USA

ABS brake light and traction lights are on. C1391 internal failure in brake actuator assembly.

- Lafayette, LA, USA

Brake actuator

- Plantation, FL, USA

I was at an automatic car wash yesterday and after the wash finished I pulled out of stall with hardly any brakes.I was not able to pump them and had to take my car into a mechanic the brake actuator was out and the car is undrivable.the price for the part alone is over $2500 I was informed by the dealership that is was a recalled item but not for the yr of my car. If this would have happened in traffic or at a high rate of speed I know I would have been in a serious accident and I could have killed someone.

- Corpus Christi, TX, USA

When I go over a bump or pothole and put on the brakes the car accelerates. Toyota claims it is just how the ABS brakes feel, but the car actually speeds up when I brake. Happened multiple times since I bought the car. So far no accidents.

- Closter, NJ, USA

While in motion when I pressed the brakes the pedal went to the floor. Brakes failed. Rapid beeping with brake light on. I pushed on the brakes and there was nothing. I did some research and this vehicles are having a problem with the brake booster assy. There is a recall for the same parts for the 2010 Prius, not 2011 - 2015

- Vega Baja, PR, USA

Three weeks ago the brakes failed at a stop light on a city street and the ABS and brake lights came on in the dash. The brake fluid appeared to be low so we opened a new bottle of fluid and filled the reservoir which seemed to temporarily remedy problem and nothing could be diagnosed because no lights were on in dash. The exact same thing happened again with the brakes failing and the dash lights coming on while at a red light on a city street. We had to have vehicle towed and were told it was the master cylinder assembly, booster pump etc. And wasn't covered under warranty at $6400. The car has 82,925 miles and has been maintained.

- Mesquite, TX, USA

I've had my Prius from 4-14 to the present 2016. I keep having issues with the dealership I take it to for repairs. [xxx] in la crescenta ca. After mentioning and describing issues, the staff there says that unless the dash lights up with a message and gives a code, they cant fix it. So in order for them to look into it any further than me telling them dash light is nec. I've told them about the ac noise from the first say I took the car in to get services at 33K. They say they don't hear or see anything. My ac compressor sounds like its going to explode when ac is on. Brakes have been extremely diff. To explain because of terminology. They seem to lose their power when being pressed and ABS seems to malfunction?? so they drive it and tell me its nothing I need to worry about and will be fixed when changed. Change brakes and the prob persists. Not only ABS but Firestone says my hardware has issues as well. I bring it to the attention of the staff and nothing seems to get done about it... my odo. Speedom is/was off +2 mph. My weather seals have been stripped and ripped off the vehicle which now causes water leaks from every crevice.. and the biggest two of all my complaints are 1- hybrid batt. Fan never worked and I wasn't told...hyb batt has never worked properly (drains way too fast when stopped at a light or in traff) along with the heat created by the batt and the engine that fill up the cabin and will have the temp raised upwards of 90+ on a 75 deg day. 2- the ECU's ipm's (or something like that) has not been calib. Or updated. Even received coverage stickers from toy headquarters stating full coverage if a.B.C. (listing of problems or malfunctions) I describe the exact same symptoms to them and get the same response"no code, no fix" help and ps I just checked the VIN online 4my veh & it says a diff package w/a bunch of extras that I never got upon purchase"??_hmmm?" information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- South Pasadena, CA, USA

Hard knocking when turning on engine until I compress and decompress my break. Has happened 3 times, only during the cold months

- Lawrenceville, GA, USA

When I'm braking and slowing down gradually, as when approaching a red light, the brakes momentarily stop working and the car feels like it surges forward if it hits a low-traction surface like a pothole or manhole cover or wet spot. I saw there was a recall for this in 2010, but 2011 model consistently does it and has caused me and my friend to nearly rear-end other cars when driving my car. Apparently, it pertains to the regenerative braking system being turned off when the ABS engages, leaving only friction brakes. This happens several times a week on the wet roads where I live (near seattle, Washington). This has happened since I bought the car new in 2011 but I'm complaining now because my friend borrowed it and almost rear-ended someone and pushed me to report it.

- University Place, WA, USA

When the brakes are pressed, if you hit a bump or pothole, the brakes lock and the car hydroplanes forward. I hit the back of someone because of this defect.

- Wayne, NJ, USA