Service Brakes Problems of Toyota Prius - part 1

Brakes went soft with little braking power. Traced the fault code to a faulty braking actuator; Toyota says this is past the coverage date for the recall.

See all problems of the 2012 Toyota Prius 🔎.

While driving, the vehicle experienced a sudden brake system malfunction without prior warning or gradual degradation. The vehicle was being operated under normal driving, road, and weather conditions. No recent brake service, repairs, or aftermarket modifications had been performed prior to the failure. Multiple warning lights illuminated on the dashboard, including the abs warning light, brake warning light, and traction control warning light. Shortly after the warning lights appeared, the vehicle began emitting continuous warning beeps. Audible buzzing or pumping noises were also present from the brake system during the malfunction. During this event, brake performance was reduced and braking felt inconsistent. The brake pedal became hard at times and spongy at other times, requiring increased effort to slow the vehicle and resulting in unpredictable braking response. This created a safety concern while the vehicle was in motion. The driver was forced to alter driving behavior and exercise extreme caution due to reduced braking confidence and unpredictable pedal feel. The malfunction has occurred intermittently during normal driving. The condition temporarily resolves on its own and later reoccurs without corrective action. The suspected failed component is the brake actuator / abs actuator assembly. A diagnostic scan retrieved fault codes c1252 (brake booster pump motor on time abnormally long), c1253 (pump motor relay malfunction), and c1256 (accumulator low pressure), which are consistent with brake actuator malfunction. The failure occurred at approximately 154,000 miles. This vehicle model and generation have a documented history of premature brake actuator failures with similar safety-related symptoms reported by other owners. The condition places the driver and others at risk due to unpredictable braking behavior, reduced braking effectiveness, and repeated warning alarms while driving. Warning lamps and audible alerts continue intermittently.

Warning lamps for abs and others and the chiming dings came on while pulling away from the bank drive through and parking for a second. I shut the engine off and turned back on with no success. I was barely able to park in a spot because of difficulties braking. My car had been making an electric noise every 15 seconds or so previously, at different times when parked, but I thought it was the hybrid engine. Now I think it was the brake pump trying to build up pressure due to a faulty, leaking brake actuator.

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The abs failed while driving on the highway. There was no accident, but it was substantially harder to brake when needed.

See all problems of the 2015 Toyota Prius 🔎.

Abs, slip indicator and brake warning lights have appeared on the cars dashboard. Dtc fault code c1391 has appeared indicating a failure of the brake booster and brake booster pump assemblies per Toyota customer support bulletin (zjb) no. : pol18-03. Loss of regenerative braking, putting the safety off occupants at risk.

See all problems of the 2011 Toyota Prius 🔎.

The abs brake actuator in my 2013 Prius v failed at just over 91,000 miles in December 2025, making the vehicle unsafe to drive. I understand that this is a known issue with this model of vehicle.

The vehicle has 95k miles on it and both brake actuator assembly and booster pump have gone bad. This is a defective issue, I called Toyota and was told too bad since the program that fixed this ended 02/25. The car met the mileage requirement, but being 10 months out of the date gives Toyota the right to wash their hands on a defective part. The part is over $1500 just in parts to replace! this is wrong on their part. Not one option offered.

This vehicle has 95k miles, now the vehicle has a brake problem which can cause deadly problems. The parts that have gone bad on this car are defective parts that Toyota knows about. The warranty they extended for this ended in 02/2015. They had 150k miles or 10 years limit on that warranty. We are well under the mileage and 10 months over according to Toyota. Can’t believe they will dismiss something this delicate and dangerous. The parts are not cheap and it’s something we can’t afford to fix right now. I can’t believe Toyota will just wash their hands on something this important in a vehicle. This is a know defective part! they should have some sort of responsibility and resolution. I called and was told they cant do anything. Even a part offer so we can fix nothing. Please review this and hopefully you can help.

The brake system malfunctioned suddenly. While driving and while stopped, the brake pedal became very hard and braking behavior became unpredictable. The vehicle sometimes brakes aggressively and other times requires excessive pedal force to stop. The abs and brake warning lights illuminated. The vehicle no longer provides normal braking assistance. This issue is related to a failure of the brake actuator / brake booster, which is a known issue affecting Toyota Prius models from 2010 to 2015. This defect creates a serious safety risk, as braking performance is inconsistent and may increase stopping distance or cause loss of control during emergency braking situations. The vehicle has not been repaired yet because the cost is very high and the manufacturer has declined assistance despite this being a known safety-related defect.

See all problems of the 2014 Toyota Prius 🔎.

Red brake light came on, traction control light came on, abs light came on, Toyota says my brake pump needs replaced. That my brake will fail.

Upon acceleration, several brake related warning lights came on along with a consistent chime. When it came time to stop. The vehicle would not stop then with great pressure on the pedal, I was able to slow the vehicle narrowly avoiding a collision with another vehicle. The vehicle then drove normal after that and a few minutes later the lights went out. When I got home, I scanned for codes and got c1252 and c1256. This appears to be a common problem with these vehicles that Toyota does not want to address.

My 2012 Toyota Prius plug in hybrid had just passed state inspections and was even looked at by a dealership a year ago with no reported issues. I brought up a whirring issue at the dealership when breaking but the dealership said that’s normal for a hybrid. In a matter of minutes while driving, the traction light, brake light, and abs light came on as well as a groaning, whirring sound when breaking. Over time, the breaks failed and I could not stop the car, almost causing a wreck because I could not stop without putting all my body weight on the break pedal. When taking it to the Toyota dealership for a whole diagnostic, they said it was a break actuator and break booster failure that is known to happen with Prius’s. They quoted me $3000 for a repair and then marked my breaks as yellow not red on their sheet implying I could still drive it despite the dangerous situation of driving without functioning breaks. When looking into it, this seems to be a known and common problem with Prius’s due to a faulty manufactured part. Codes were c1391, wc1256, and c1252. I believe this part should be recalled and Toyota should fix these faulty parts, especially considering they inspected my car and did not mention it as an issue despite it being a known issue. I got a second opinion from mavis tires and they concurred with the diagnosis but could not fix it.

The brake accumulator went out thanksgiving day on my way home nearly causing an accident. I also missed dinner due to the issue creating a clearly unsafe driving condition where I was barely able to use my brakes. This is a known issue by Toyota, whom extended the warranty to 10 years. Of course, my warranty was 3 days past the 10 years even though it is under the mileage requirement. This should have been a recall, as it is a known and reported problem. I am now out 3300$ for the repair just to get my car in an operable condition. There were no warnings, the abs light as well as the traction alert went off and I lost the ability to properly brake in an instant. There was no warning, nor was I notified about this part.

The power assist braking system failed while I was driving in the rain. I was approaching a stoplight and I had to push down a lot harder and farther than I typically have to in order to stop. Luckily I was not going that fast and there were no cars ahead of me, but I stopped beyond where I had intended at a busy intersection. No warning lamps or messages had been illuminated prior to this happening. After the failure, the brake system, abs, and slip indicator lights were on and remained on when the car was restarted. An independent service center used a scan tool and found code c1391 stored in memory, indicating that the brake booster is unable to hold pressure due to an internal leak. The vehicle has not yet been inspected by the manufacturer, police or insurance, but can be available upon request.

I bought this car over a week ago for a good price, performed fine until I’m driving it home on the interstate and some abs/brake lights came on the dash. I enter my city and notice the brakes aren’t performing as tight as they were during the test drive. A few days later I take it to a local dealership to get it looked at. The brake actuator and pump had gone bad, causing this issue. It cost almost $5,000 to fix there, I couldn’t afford it so I had to only pay the $185 for the diagnostic. It’s an on and off thing, sometimes the lights go away and it brakes as it should, but most of the time the lights are on and the brakes don’t work as they should. I fear one day the brakes may eventually give out on me and cause an accident. I am available for inspection.

On [xxx], we were driving from coalinga, CA to phoenix, az for thanksgiving. As we began to descend into los angeles on [xxx], three warning indicators suddenly went the abs warning light, the traction control light and the brake warning light. The brakes still worked but the brake assist was weakened. We pulled over as soon as possible at the nearest autozone. The employee performed a standard handheld obd-ii scan of the vehicle and did not detect any issues. We continued on our way through los angeles and to san bernadino where we were spending the night. At one point the indicator lights went off for a few minutes but then came back on. We spent the night in san bernadino, and the next day (11/26/2025), we took the car into the san bernadino Toyota dealership as we felt it was unsafe to keep driving. The dealer conducted a thorough full brake and hybrid system diagnostic and confirmed that the failure was inside the brake booster system. The repair estimate states: "brake booster assembly with master cylinder and brake booster pump assembly have an internal leak. " thus, Toyota's own technician identified an internal hydraulic leak within the booster system, affecting the booster assembly, master cylinder, and booster pump assembly. The total repair estimate is $3,959. 99. This is a major safety defect affecting sealed hydraulic components that are not part of routine wear-and-tear. There were 4 people in the car. Fortunately, the brake failure did not result in an accident, but it could have if we had kept driving on to our destination. We contacted the Toyota brand engagement center to ask for goodwill assistance, but they were unable to help us. In addition to the repair costs, we have incurred rental car costs. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The master cylinder started failing while I was driving the car, the car only has 138k miles, the dashboard lit up like a christmas tree, all the warning lights were on, and when I went to step on the brake, I had to push it all the way to the floor for any braking to happen. I remember being scared for my life because I had almost no brakes which I could've got into a serious accident or been killed had it failed completely. I took the car to the dealer and they diagnosed it with code c139: abnormal leak at accumulator assembly, and recommended a new brake booster with master cylinder assembly and brake booster pump assembly with bracket. The car by age was not in Toyota's extended warranty on the parts but mileage-wise it still is, so I was footed with a $4-5k bill to replace both parts.

While driving, suddenly all brake lights and warning lights went on, and brakes stopped working normally. It became difficult to brake (brake took a while to engage - had to press pedal to the floor). After diagnostics at the dealership it looks like the brake booster failed. Apparently Toyota knew about this issue as they did an extended warranty through a customer support program, but unfortunately my issue occurred just past the expiration of that warranty. Since brakes are such a critical component of vehicle safety, if they don't operate well or as expected, it endangers the driver and everyone else on the road. It is wild that Toyota is aware of this issue but that there has been no recall yet.

Brake actuator failure requires actuator and master cylinder replacement. All dash lights came on while driving. The vehicle was diagnosed at brian easler Toyota in hendersonville north carolina. The brakes are still operational temporarily but spongy and expected to fail so the car is not drivable. I expect to have the actuator and master cylinder replaced in then next few weeks at a cost of $5600. I see there were previous recalls on the braking system that have now expired.

Brakes had no stopping power. Normally when braking it was smooth. All the lights went on. Toyota dealer confirmed that the brake booster pump assembly and brake master assembly needs to be replaced.

My daughter was driving the 2013 Toyota Prius on the interstate in chattanooga, TN. The brakes did not feel right and the car was very difficult to stop. (it did not brake at a normal distance) my daughter was able to get someone safely, and she had the car towed to the dealer. My daughter's life was endangered by this brake booster failure, but there is no recall listed on the vehicle. Also, when I googled the issue, I found that it is a well-known and common problem in this year Prius. The brake booster failure is due to a Toyota design flaw, and Toyota is apparently being sued for it. Why is this issue not listed as a recall? I would not have allowed my daughter to drive around in a car for which the brakes are known to fail. How many accidents and deaths will be caused by this problem before Toyota stands behind their product and recalls affected vehicles? I had to pay $3200 for this brake repair, even though it is caused by Toyota's design flaw and endangered my family's life. My family owns four Toyotas, and I do think they make the most reliable vehicles on the road. I cannot understand why there is not a recall, and they are not standing behind their product.

VIN: [xxx] year/make/model: 2011 Toyota Prius mileage: 87,433 date: 11/4/2025 description sudden 80% brake loss. Loss of abs brake light + abs + traction control lights on dash (photo attached). Known failed brake actuator (c1391) — identical to 500+ complaints in pe19-004. Toyota corporate denied coverage (email attached). This is a safety recall issue — please reopen investigation. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Brake actuator went out on 2013 Toyota Prius gen 5. The part is very expensive and in my opinion is a part that should not have to be replaced. The care has 120,000 miles. It is driven very softly, meaning not fast and hard but commuting to work and grocery store as needed. A nice commuter. It is not fast but gets you there. The actuator put me at risk as stepping on the brake was hard and the car did not want to stop and I was close to hitting the car in front of me. All the lights came on at the dashboard and I was very scared to continue to drive and had to get a tow truck.

The abs, break, and traction control, suddenly turned on when I was traveling on the freeway in mild traffic. I was traveling at about 60-65 mph. I attempted to use the breaks and could feel a substantial difference in how much and how hard I had to push in order to stop. The problem has not been confirmed by a dealer or service center. The vehicle was inspected by my brother in law who works on cars frequently. There were no warning symptoms prior to the problem. The problem first occurred on Saturday November 1st at about 12:30. According to my brother in law, it was the break pump that failed; you can hear air escaping when you push on the break pedal.

My 2013 Prius plug-in hybrid with 131k miles on it showed the abs, brake, and traction control lights while driving last week. Diagnostics from auto shop showed dtc code c1391. System is available for inspection upon request. Safety is definitely at risk, since I am needing to drive it around to assess the issue, and brakes could fail at any time. Vehicle has not been inspected by the manufacturer, police, insurance representatives or others. After speaking to Toyota, I was informed that--although under 150k miles--my car is not covered by the extended warranty because it is 2 years past the 10 year requirement. I drove my car very little between 2020-2022 because of the global pandemic. This is a very common issue with 2012-2015 models caused by a defective part, and it's likely that the problem does not commonly present itself until after the warranty expires.

The brakes suddenly failed in our 2013 Prius v while she was driving with our two young children. It was extremely scary, and very dangerous. Toyota has known about the braking system issues for years but refused to offer a recall to avoid costs. This needs to be immediately addressed.

The contact owns a 2014 Toyota Prius v. The contact stated that while driving approximately 35 mph, the brake light, tire pressure, traction control, battery, and other warning lights were illuminated. While attempting to depress the brake pedal, there was more resistance than normal, making it difficult to slow the vehicle. The contact was able to drive the vehicle to the nearest mechanic; however, the vehicle was not diagnosed. The vehicle was then taken to the residence. The vehicle was taken to another certified mechanic, who diagnosed and determined that the brake master cylinder and actuator assemblies had failed. The brake master cylinder and brake actuator assemblies were in the process of being repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 220,000.

The contact owns a 2015 Toyota Prius. The contact stated that while driving approximately 15-20 mph, the abs, brakes, and the traction control warning lights, and the malfunction indicator light were illuminated. Additionally, the vehicle hesitated to respond while depressing the brake pedal, causing the braking distance to be extended. The vehicle was taken to the dealer, where it was diagnosed with an abnormal leak in the accumulator and a leak in the brake booster pump. The dealer determined that the brake master cylinder and the brake booster pump needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 94,100.

The brake booster fail and I'm at like 140k. It was very scary when it happen to me today. I press on the brake think it would brake like normal but no. It kept sliding. I felt like I was going to crash. I don't have any paper report on it yet but they are certain it's the brake booster.

Last night, the brakes stopped responding, warning lights came on (abs warning light, brake system warning light, and the slip indicator light). This morning, a local auto repair shop diagnosed the problem as a failed brake booster assembly. This is a safety issue and we have been told we have no option but to pay to replace the entire assembly. The repair shop has contacted the local Toyota dealership, from which we have to purchase the replacement brake booster assembly.

See attachment.

See all problems of the 2019 Toyota Prius 🔎.

Returning from a trip, several brake and skid related dashboard light illuminated. I pulled over and was able to stop the car and took it directly to the Toyota dealership after calling them. Brakes felt very spongy and stopping distance was increased. The dealer informed me that this was a known problem with my model but that I was not eligible for recall or extended warranty. I have also seen a number of complaints of this issue on the internet. The cost to repair the issue was over $4800.

While driving 60 mph in highway, abs, traction control and brake lights lit up and vehicle lost its effective braking power. There were no prior warnings prior to this failure. It was a sudden incident. Since it wasn't rush hour, I could safely reduce speed and bring the car to stop. Situation could have been much different if it was normal hours. After taking the car to dealership, it indicated dtc code 1391, brake assembly failure. The car was fixed at dealership at cost of $3,000. When researched further, it appeared that there is broader pattern of failures. Numerous reports have been made by owners of 2010–2015 Toyota Prius, Prius phv, 2012–2015 Prius v, 2012–2014 camry hybrid, and 2013–2015 avalon hybrid vehicles, all of which share the same brake booster pump assembly design manufactured by advics CO. , ltd. Dealerships, including capistrano Toyota and claremont Toyota in California, have previously petitioned NHTSA regarding this very defect. Their 2019 letter to the agency documented that Toyota: * knowingly excluded hundreds of thousands of hybrids from prior safety recalls (doh 13v-235 and kol 19v-544) despite identical failures. *issued “post-failure” repair programs (warranty enhancements zjb, zkk, zkc, zlm, 20le03, 23te06 and 23te07) only after owners experienced brake failure. * identified the same dtc codes (c1252, c1253, c1256, c1391, u0293) in both recalled and unrecalled vehicles—codes that correspond to accumulator leaks, loss of brake pressure, and failure of brake assist and stability control systems. * admitted through technical service bulletin TSB-0130-19 that these defects caused loss of hydraulic pressure, increased stopping distance, and total loss of brake assist in affected hybrids. In short, the defect pattern across multiple hybrid models is identical to those already recognized by Toyota and NHTSA under prior recall campaigns, but for reasons unexplained, Toyota limited the recall population and left many consumers unprotected.

I had my car serviced oct 21 and when I picked it up the vehicle brakes made a whooshing noise and felt spongy. I thought it must be ok as they had just serviced it but when it became apparent this could be a problem I took it back Nov 1 and was told the hydraulic brake booster pump needing replacing at the cost of $3400. I was shocked as they told me it could break completely at any time but the brakes would still work. I decided to drive it home as that is an enormous car repair bill and I would have to get financing or get a different car. I didn't want to make rash decisions. I investigated the issue and found out this was a recall for these vehicles for 2010 through 2019 models. This same dealer did not mention this to me at the time of sale, that they had been subject to a recall, and since I did not have them inspect the car immediately after service (I had to miss work and my son drove me after he was off work and I feared they would close before I arrived so I had them park the car outside and the sales desk had the key). I thought I would drive it but after reflection I do not want to endanger other people if my brakes fail. This is a clear violation of the public trust that these cars are yet on the road.

While driving the 2013 Prius hybrid , the abs , brake light, and traction control lights came on. The brake was rock hard and the car would not stop at the light, causing me to swerve away from the cars in front of me and pull into a nearby parking lot. The brake would not work. There is a constant beeping noise in the car , which is a brake warning. I looked up the problem and just like many other Prius owners, there is a brake booster and brake accumulator issue and Toyota is not owning up to this problem. Many Toyota Prius owners are complaining of this loss of brakes issue. How long until NHTSA forces Toyota to do a proper recall about this very dangerous loss of brakes issue ??? they recalled a few vehicles, but the recall does not seem to cover many Prius vehicle owners that are complaining. Mine has 140 000 miles now, but this part is failing even on cars with 40 000 miles. Toyota knows very well that they have a big serious issue costing upwards of $4000 to fix. They are just refusing to recall this issue. Nhtsa has to address this issue please. They are many complaints about this loss of brakes issue.