Service Brakes Problems of Toyota Prius - part 2

Failure of the: pump break booster actuator had it towed to Toyota and they said it’s a $3,500 repair.

See all problems of the 2015 Toyota Prius 🔎.

I am experiencing the issue described in the brake booster and brake booster pump assemblies recall issued by Toyota for the Prius, which for me ended in 2023. The vehicle is unsafe to drive without performing this $4000 repair (dealer cost), which is almost more than my car is worth. Toyota should issue another extension for the repair coverage since they are known to be faulty. The previous recall and extension of the recall can be found here: [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2013 Toyota Prius 🔎.

The abs system and the brake actuator began to fail, which triggered multiple warning lights. The Toyota dealership service department confirmed that the anti-lock brake system and the actuator needed to be replaced, a $3800 value.

2015 Toyota Prius abs warning light came on . Went to car mechanic . Brake actuator & pump code leaking. It happen on 7/27/25 under 100,000 miles. Currently anti sway and abs braking disable.

While driving my Prius on the highway, the abs and traction control warning light suddenly came on. The brakes started feeling different right away, and it didn’t feel safe to drive. I took it to a Toyota dealership, and they found that the brake booster and pump had failed. I looked online and saw that many other Prius owners had the same issue, so it doesn’t seem like an isolated case.

Brake getting stuck on the floor would have to press on brake really hard just to get a response, this will happen out of the blue! driving in highway or just driving off the driveway. I almost hit a car in front of me due to lack of brake, I had to swerve to the side! first appear 1 day after buying the car. . This issue needs to be worked on right away.

See all problems of the 2012 Toyota Prius 🔎.

Abs brake pump actuator booster failed. It is available for inspection. While driving, I started hearing a hissing sound from my brakes. I tried to slow down and my several diagnostic lights (abs, traction control, brake, check engine, etc. ) flashed on while my brakes failed to work properly. I turned on my hazard lights immediately. I was in the middle of the road with my toddler in the car and I almost rammed into the car in front of me. Luckily I was able to pull into a turn lane and pushed with all my might on the brakes and it finally was able to stop. My brakes failed and I could have hit the cars in front of me and hurt my child, myself and others. It was terrifying. Problem has been confirmed by an independent service center. The warning lamps only appeared while the issue was happening and my brakes failed to work properly.

See all problems of the 2014 Toyota Prius 🔎.

There has always been this ringing sound when releasing the brakes. I had it looked at and was told there was no issue. Then while driving it felt like the brakes locked and all of the sensors came on the dashboard. I had those scanned and was told they were sensor issues but car started driving/braking ok. Few days later everything locked up. I can’t push the brake at all. I was told the brake booster pump assembly with accumulator was shot. So I began research and saw hundreds of complaints for the exact thing in my make and model and year. This could have killed someone had it happened on a highway. This should be a recall, major issue that numerous are experiencing.

While driving on the freeway I applied the brakes and the brakes suddenly felt soft and not very responsive. At that moment 3 dashboard lights turned abs, brake, and the slip indicator lights. I carefully got out of the freeway, parked the car, and had the car towed to an independent mechanic. The mechanic detected brake booster and actuator problems, code c1391.

C1391 - abnormal leak of acc pressurization. Bad brake booster assembly.

Brake actuator and abs accumalator failed. It is a common failure reported by multiple owners on these cars. I was on the high way going 70 when it failed and lost any brake boost I had putting me in a very dangerous situation where I narrowly avoided an accident. Upon scanning the car's codes I got code c1391 which I looked up and saw a bunch of other people who were also struggling with this issue.

What component or system failed or malfunctioned, and is it available for inspection upon request? brake actuator failed requiring replacement of booster assembly with master cylinder and booster pump assembly how was your safety or the safety of others put at risk? this greatly impacted braking and stopping distance has the problem been reproduced or confirmed by a dealer or independent service center? yes, Toyota dealership has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? yes, Toyota dealership were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? no. These lights appeared after the failure - brake, abs, traction control.

See all problems of the 2010 Toyota Prius 🔎.

For last 4 years I have been noticing a hissing sound when brake pedal is pressed. At first it was unclear to me where it could be coming from, and no indicator light has triggered. I have brought this to the attention of Toyota dealership when I first noticed it and the individual couldn't really make out what it was. The sound has now gotten worse, and upon further studies I am learning that there was indeed a recall pertaining to the brake booster and actuator, but my car for some reason is not included. This is a major safety issue and I expect Toyota to help resolve. Please help.

Brake light + abs + traction light came on and the brake became harder to control. I was driving in the rain and briefly lost control. Fortunately, no accident.

The brake accumulator has failed on our 2013 Prius at 170k miles. The brakes are unresponsive and all brake-related indicator lights are on. The vehicle is unsafe. This is a known issue for this model and year Prius, yet Toyota did not issue a recall. Warranties were extended to 150k miles, but this issue is a serious safety risk - danger to us and others on the road. This issue should have resulted in a safety recall, not a "courtesy" warranty extension. Toyota needs to resolve this for all affected vehicles.

The abs brake booster/accumulator is going out and this has been a known issue with Toyota for years. Mine was purchased used a few years ago and had no issues until recently, as the pump is running more frequently.

See all problems of the 2008 Toyota Prius 🔎.

Recently the dash board lights started intermittently coming on. When they are on, the brakes do not work until pressed all the way to the floor and even then the car takes a long time to stop. The lights will randomly turn off and suddenly the car brakes work normally again. It is happening intermittently with no rhyme or reason as to when it will happen. It's scary to drive because I dont know if the brakes will work or not and I almost ran into another car when trying to stop at a stop light. I took the car to be inspected at the Toyota service center for $190 and after inspection they said the brake booster and master cylinder assembly need to be replaced and it will cost $2300.

2013 Toyota Prius v has 3 recalls for the same issues but my VIN # says there isn't any recalls associated with it. I need help. It stalled on me on my way home from work luckily not on the high way now it's throwing code c1310 c1259 c1241 it won't crank all it does is click. I replaced 12v batterychecked all connectors.

My name is [xxx] ,I am filing this report on behalf of my daughter [xxx] the driver of the vehicle that involved with the unintended acceleration on the 2009 Toyota Prius . On a good clear morning on [xxx] . My daughter drove the 2009 Toyota Prius to work- when she enter to the parking lot at the speed round 5 mile/hour . Just when she was making a left turn on to the entrance gate with her left foot on the brake pedal . On a sudden the vehicle rpm unintended rev up too high and the vehicle had an unintended accelerating to move forward aggressively causing lose control of the steering . Also she could not brake even though her left foot was on the brake pedal and pressing hard to try to stop the vehicle . . This dangerous incident causing her Prius to bumped into the electrical gate panel control box . The accident caused some damages to her Prius and to the entrance gate control box though no body was hurt . But it got us through the terrible experience because it could kill some one for sure . My daughter been driving this commute car daily in the past 5 years and she has the skill of 20 year driving with good record . This Prius of her still have all oem equipments with no add- on parts-,no modifying part on any systems what so ever- and no extra floor mat cause we been warned before about the possible of unintended acceleration causing by aftermarket floor mat to any vehicles. . We feel unsafe after the mystery accelerating problem on Toyota vehicle that could take people lives . So the mystery unintended accelerating on car is real . I am currently checked and find out her Prius has 2 incomplete recalls (un-notice to us ) but none of them related to the unintended acceleration problem . We would like the NHTSA to take this problem seriously to save people life . I will included photos of this incidents and willing to provide all information if needed to address this problem, again to save lives . Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 5.

Omponent/system involved: service brakes, hydraulic ? make: Toyota model: Prius year: 2015 mileage: 155,470 VIN: [xxx] ? what happened: my 2015 Toyota Prius is experiencing brake failure symptoms related to a known defect addressed in Toyota’s warranty enhancement program zjb. The vehicle has triggered dtc codes c1256 and c1391, which indicate failure of the brake booster and master cylinder — a problem widely reported by Prius owners. The defect causes decreased brake effectiveness and increased stopping distance. My Prius is just 5,470 miles over Toyota’s 150,000-mile coverage cap, and despite confirming the exact codes, the dealership refused to repair unless Toyota pays first. Toyota corporate opened case #[xxx], but has not offered a resolution. This is a safety-critical issue that Toyota acknowledges in internal service bulletins, but they are denying assistance based on a technicality, despite my vehicle having the exact failure their program is designed to address. I am filing this complaint because I believe Toyota is avoiding responsibility for a dangerous manufacturing defect affecting braking performance and safety. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

I started hearing a scratching/rubbing noise from the brake, and feeling the scratching/rubbing through the brake pedal, making it difficult to push down. I almost crashed in the ally into my garage, but the emergency braking took over and stopped the car very suddenly, snapping my neck a bit, and it is still sore as of me writing this report. Since then brake pedal makes scratching/dry rubbing noise with heavy rubbing and grabbing feel through pedal. It only happens at 20mph or below during quick stops (not smooth stop, press pedal quickly), at 15-25% pedal position. When holding pedal at that position while moving, rubbing/grabbing through the pedal feels rhythmic like it's related to wheel rotation. If car is creeping in neutral or drive (no gas pedal pressed), and you lightly press the pedal, you can hear and feel like something is grabbing/releasing/grabbing/releasing. Sometimes it the brake pedal resists and there is a very loud rubbing or grinding noise, and I have to press the pedal very hard. This can also be replicated when the car in in park. Lightly pressing on the brake pedal causes the braking pump to make a whirring sound to build pressure (this is normal), but at the end there is a scratching sound and grinding feeling in the pedal. I took it to the dealer 3 days after purchasing it on June 25th, 2025 and the assistant service manager reproduced the issue in front of me, and thought it was the brake actuator going bad or something with abs. However, the master tech at the dealer just drove it around, did not check any components except the thickness of the brake pads, and declared everything fine. I fear for my safety in this car. If I am involved in an accident, it will be because the braking system failed in this car and the dealer refused to fix it.

Break booster issue. Car only has 63,465 miles. Toyota has received reports about certain internal malfunctions of the brake booster. Problem is, not many have had luck getting the part covered because it's likely that the problem does not commonly present itself until after the warranty expires.

The abs system has failed, and I have to pony up $3000 + for repair, since the warranty extension from Toyota has expired - 10 years since first use (even though I have only had it for 5 years). I have less than 150,000 miles on this car, which is the the other parameter for service coverage for this problem. Toyota knows these parts fail, and they extended the warranty, but there is no recourse if your car is over the 10 year limit, even if under the mileage limit. It is a safety issue and should be addressed no matter the age of the car. I can't afford the cost of repair and so will gamble on not needing to use the antilock brakes.

While driving on the interstate I went to slow down to merge and my brakes failed. The following warning lights came master warning light (yellow), brake system warning light, brake system warning light (red), abs warning light, and the slip indicator light. My vehicle was towed to a Toyota dealership and after running a diagnostic test, they confirmed that it was the "break booster with accumulator c1391 stored internal leak of accumulator and need immediate attention" which they quoted at $4,295. 68 to fix. After researching the issue saw a customer support program 20te07 was issued taking responsibility for the faulty brake booster pump assembly however only covered the repair for a two-year period and only if it was one of the identified diagnostic trouble codes listed in the csp issued by Toyota but expired in Feb 2022. The code pulled from my vehicle 3 days ago was listed in this document, but the coverage only covers until Feb 2022. This is not a normal wear and tear issue, it is a faulty part that Toyota identified as a life and death safety concern but refuses to do anything about because mine didn't show an issue within their 2-year csp timeframe. Toyota identified that there are roughly 118,950 2012-2014 model year Prius v with a production period of late September 2010 to mid-November 2014 vehicles that this faulty part affects along with everyone else on the road with these vehicles as it causes failure of the brake booster pump assembly, which leads to a loss of braking assist and the deactivation of the vehicle stability control system. For the safety and lives of the owners of these vehicles and all of the other lives of the drivers on the road that this could affect in the case of this faulty part should there be a catastrophic accident, like mine could have been, a nationwide recall on this part must be issued.

I am writing to express my profound concern and disappointment regarding a recent, terrifying incident involving the brake system of my 2014 Toyota Prius. On Saturday, June 21, 2025, while driving with other passengers, my vehicle experienced a complete and sudden brake failure. Multiple warning lights illuminated on the dashboard, and despite my efforts, the brakes became unresponsive, making it impossible to stop the car. The sheer terror and helplessness I felt in that moment, with the very real potential for a catastrophic accident involving myself, my passengers, and other road users, is indescribable. Fortunately, through sheer luck and quick thinking, I was able to make an emergency stop on the side of the road, preventing any collision or injury. However, the emotional toll of that experience, the lingering stress, and the fear of a recurrence remain significant. I was subsequently informed that the cause of the failure was a leak in the brake accumulator. I am attaching the diagnosis and repair invoice. The necessary repairs were not completed until Wednesday, June 25th. This unforeseen and critical malfunction also necessitated the expense of a rental car for four days, adding to the financial burden and inconvenience. My frustration is compounded by the fact that this brake accumulator issue is a well-documented and known defect in Toyota Prius models, specifically affecting 2010-2015 vehicles. Toyota itself has previously issued a technical service bulletin (TSB t-sb-0043-13) acknowledging this problem and offering warranty extensions for affected vehicles, typically up to 10 years or 150,000 miles. Despite this being a recognized safety concern, I was informed that my vehicle falls approximately eight months outside the 10-year warranty period, thus disqualifying me.

Prior to issue, noticed a buzzing sound from engine compartment, later known to be the abs accumulator pump, occurring more frequently - first multiple times when braking, then later continuously while driving. Dashboard eventually lit all brake-related warning lights ("brake", tsc, abs) and brake pedal behavior changed markedly. This occurred after parking in my driveway while engaging the parking brake. Brake behavior during and after this period was wildly inconsistent and impossible to predict. At times the brakes would perform normally, but most often the first portion of brake pedal travel would have no braking effect, and actual required force on the pedal to brake was greatly increased. The need to press further and with more force created a dangerous situation as it delayed how quickly I could slow or stop. The inconsistency in performance created a dangerous situation as the vehicle may (and did) sometimes stop more suddenly than expected. Additionally, the failure resulted in loss of traction control and abs resulting in greatly increased risk in wet road conditions and terrible danger in sudden-stop situations. Self scanner & Toyota service center confirmed presence of c1392 code and recommended replacing brake actuator and brake pump assemblies, quoting over $4,500. Service was declined and replacement parts bought from Toyota and self-installed to resolve issue. Both Toyota service center and Toyota customer support line confirmed that this issue was described in an existing customer support bulletin but that coverage was denied due to age of the vehicle. Vehicle was approximately 15,000 miles below listed mileage cap but approximately 12 years old, with Toyota denying service for vehicles over 10 years old.

Require replacement of brake booster pump, decreased braking ability.

Failure of brake pump and brake cylinder assembly system, resulting in reduced braking ability and stiff brake pedal. Per Toyota's diagnostic: trouble code c1391 is present, abnormal leak in accumulator, replaced brake abs actuator assembly, along with brake master cylinder, and bleed the brake hydraulic system. No warning lamps or safety indicators prior to failure. Upon failure (while on freeway going 50+ mph) the abs, brake, and traction control warning lamps illuminated. The failure resulted in no accident or injury, however it did occur while on the freeway going freeway speeds, and resulted in difficulty in braking, which was dangerous. Took Prius into Toyota dealer for diagnostic and repair, was told that part was known to fail in this model of Prius, and had a manufacturer designated extended warranty for 10 years or 150,000 miles. However, despite Prius being under 150,000 miles, it passed ten years since purchase in March 2025, meaning I had to pay in full for the repair ($3,631. 96). The car gave no indication of needing the repair until the day of the failure, which was on June 18th 2025. If the vehicle had given some prior indication of brake pump system failure or fault I would have had it repaired prior to the warranty expiration, but it did not, leaving me to pay out of pocket for a failed part that Toyota is at fault for making prone to failure.

While driving my 2015 Toyota Prius, the brake pedal became extremely stiff and hard to press. I was on the way to the dog park with my dog in the back seat when I had to press down very hard just to slow the car at a traffic light. It felt like I was stepping on a rock. The brakes barely engaged, and I had to use far more force than normal to get the car to stop in time. When I hit the brakes, they finally caught hard and suddenly and my dog went flying off the back seat and landed on the floor. She’s fine physically, but now she’s terrified of getting in the car at all. It was scary for both of us and felt totally unsafe. If I had been going just a little faster or if someone was walking across that intersection, it could’ve ended badly. I later found out this issue is tied to a known defect with the brake booster and accumulator system, specifically related to code c1391. Toyota even acknowledged this problem in a customer support program (csp zjb/zkk), but they refuse to help because my car is slightly over the mileage limit. That doesn’t change the fact that this is a serious, dangerous failure that affects the driver’s ability to stop safely. Toyota should be forced to take responsibility for this failure before someone gets seriously hurt.

A few weeks ago, while waiting at a traffic light, the brake warning lights (abs, emergency brake, traction control) lights on my 2013 Prius lit up and the brake pedal suddenly becomes much less responsive. I drove carefully back home, and researched online what the problem could be. To my surprise, this seems to be a known problem to Toyota, who had issued a campaign in the past to address this problem (abs actuator, pump) and to replace the known faulty parts for free, but only for owners who were experiencing a failure at that time. Now the recall has expired, and owners like me who weren't having a problem at the time are stuck in a situation with cars that have a known, dangerous fault, while Toyota refuses to help with the problem anymore. The approximate cost for replace/repair is over $4000. All owners should have been included in the previous campaign, whether they were experiencing a failure or not, during that time period since Toyota knew that these parts are faulty.

Abs warning system on dashboard is intermittent. I hear computer noises near the front driver tire. Then the warning light goes out or reappears on dashboard. Issue is the expensive diagnostic fee that may not unearth the cause, and if cause identified the diagnostic fee cannot be applied to the expensive repair. That’s a hard pill to swallow —and not affordable given economy, and I just had all four tires replaced along with a wheel alignment. Also, the yellow tire pressure light now blinks non-stop. (previously it blinked 3x then stayed on but stopped blinking. ) anyways, lots of covo about same issue in the 2011 Prius chat room I found after googling “2011 Toyota Prius abs warning system. ” wondering if software needs updating, or perhaps there’s a systemic mfg defect?.

See all problems of the 2011 Toyota Prius 🔎.

6/12/25 I'm driving my 2013 Prius w 123k m through a construction zone. The road became bumpy and when I depressed the brake nothing happened. Thinking I must have hit air or be imagining things I tried the other pedal. The acceleration re-oriented me to the fact that my brakes were non-existent. Many lights I've never seen illuminated on the dash as I looked into my mothers eyes to say we had no brakes. I was somehow able to pull safely. After the initial loss of braking I discovered I had a small amount of stop if I put the pedal on the floor. The closest local shop thought most of the internal braking system related to the pump and actuator would need to be replaced but requested I get an opinion from Toyota. At drop off I had requested they top off the brake fluid, despite their informing me that was never necessary. Perhaps this repressurized the system because upon visiting the car all dash lights were off and the brakes felt normalish. The shop did not know why. This is my only transportation. At 9:30 in the am 6/14/25 I proceeded to the closest Toyota dealership w the safest direct route slowly with hazard lights and lots of space from other cars. While waiting for diagnosis I discovered this exact issue was a known defect and had been the subject of a class action lawsuit and customer service bulletin of which I had no notice. Since 2022/2023 the car had been briefly and consistently losing traction over minor bumpy conditions. Without notice of the issue I had no way to know this was a precursor to total brake failure. This car was serviced at 3 Toyota dealerships during the extended warranty authorized by the csb. I was never apprised of the potential issue, and expressly requested a list of recalls related to my vehicle at lumberton Toyota in 2022 which they refused to provide. I therefore googled recalls, but this issue was not a recall. I have never heard of a csb. Two Toyota dealers quoted me the full price to replace the braking system, $3,273. 94.

While pulling out of a parallel parking spot going slightly uphill, I braked as I looked around the back of a double parked truck. I saw a car coming, braked hard, and suddenly my car surged forward across the street and hit a parked car. I looked down and saw that my foot was squarely on the brake pedal pressing down as hard as I could. The parked car was unoccupied, and I was uninjured. There were no warning lamps, messages, or other symptoms of the problem. I turned my car into the dealer for repairs and a fix to the sudden unexpected acceleration. They could offer no fix until a Toyota representative examined the car. On August 14, by an emailed letter, Toyota claimed it found no defects and it must be the result of driver error, specifically, my mistakenly hitting the accelerator. This is gaslighting denialism. (a) the edr data sent to me does not indicate that I hit the accelerator unless that data is in the page of hexadecimal numbers. (b) Toyota's claim that I hit the breaks at "-0. 2 seconds prior to the collision" is physically impossible. No one can move their foot from the accelerator to the brake that fast. (c) Toyota's claim is contrary to what I experienced and observed.

C1391 - abnormal leak in accumulator.

Cruise control not working. Traction control light active, brake light active, and light active the cause was diagnosed by Toyota of paris. TSB for c1391 code abnormal leak in accumulator. The corrective action is to replace brake booster assembly with master cylinder and brake booster pump assembly.