Toyota Prius V brake failure problems

Filed Sep 16, 2026 · Brakes · 187,000 miles · FL

The contact owns a 2012 Toyota Prius V. The contact stated that while driving 65 MPH, brake fluid was leaking from the vehicle. While driving over 45 MPH, the brake pedal became firm, requiring the driver to exert extra force while depressing the brake pedal; the brakes failed to respond as intended. Additionally, a burning and toxic odor was present during the failure. Multiple warning lights illuminated on the instrument cluster, including the ABS system, parking brake, brake malfunction, and electronic stability warning lights. In addition, the automotive brake system, brake pump, and pressure warning messages were displayed. The vehicle was taken to a local dealer, where it was diagnosed with a failed brake booster assembly after inspection. The dealer determined that the brake booster assembly needed to be replaced. The contact associated the failure with Customer Support Program: 20TE07. The contact was referred to the federal safety agency Hotline by a lawyer, and the contact had found a class action lawsuit related to the failure. The failure mileage was approximately 187,000.

Filed Sep 9, 2026 · Brakes · CA

2012 Toyota Prius v with 89,662 miles. Multiple brake warning lights illuminated, and the vehicle stored diagnostic trouble code C1391, “Abnormal Leak in Accumulator.” The brake booster/accumulator pump is also cycling about every 13 seconds, even when the brake pedal is not being applied. The vehicle and components are available for inspection. My safety concern is that this involves a critical braking-system component. When the warning lights are on, regenerative braking is disabled, and braking behavior changes. I am concerned that continued deterioration could reduce braking performance or result in loss of brake assist. The issue has not yet been formally diagnosed by a Toyota dealer. I scanned the vehicle with a diagnostic scan tool, which currently shows C1391. I also contacted my independent repair shop, which recommended that Toyota diagnose the vehicle because this code is associated with the brake booster/booster pump failure previously addressed by Toyota Customer Support Program 20TE07. The vehicle has not yet been inspected by Toyota, police, insurance, or another manufacturer representative. A Toyota corporate case has been opened and escalated. There were no known brake warning lights before this incident. The problem first became apparent when multiple brake warning lights illuminated. Afterward, I noticed the brake booster pump cycling unusually often. Toyota previously identified C1391 as a qualifying code under 20TE07 for certain 2012–2014 Prius v brake booster/booster pump failures. My vehicle is outside the time-based coverage period despite relatively low mileage. I am reporting this because I am concerned this safety-related failure may continue occurring in similarly aged vehicles.

Filed Sep 8, 2026 · Brakes · FL

The vehicle is experiencing a critical failure of the Brake Actuator and Booster Pump assembly. The dashboard currently displays multiple warning indicators: ABS light, Traction Control light, and the Brake System Warning light (Master Warning "!"). Symptoms: Mechanical Failure: The internal high-pressure accumulator is failing to hold pressure. The electric brake booster pump is heard cycling every 10-20 seconds even when the vehicle is stationary and the brake pedal is not depressed. Loss of Braking Safety Features: The system has disabled regenerative braking and Anti-lock Braking (ABS), causing significantly increased stopping distances and a “spongy" brake pedal feel with diminished braking response. Predictability of Failure: This failure matches the exact symptoms described in Toyota's Customer Support Program 20TE07 (and previously ZJB), which acknowledges an internal defect in the brake actuator. Safetv Risk: The sudden transition from power-assisted braking to manual hydraulic braking during a drive creates an immediate safety hazard. As the pump motor continues to cycle excessively to compensate for the internal leak, it is at risk of total thermal failure, which would lead to a near-total loss of braking assist while the vehicle is in motion. Despite the vehicle having only 75,689 miles (well under the 150,000 mile limit acknowledged in Toyota's support programs), Toyota has declined to provide assistance because the vehicle has surpassed the 10-year age mark. Toyota is wrong in not providing support for vehicles whose critical components such as brakes shouldn’t experience catastrophic internal failure at 75,689 miles, regardless of the vehicle's age.

Filed May 13, 2026 · Brakes · AL

Description of the Problem Vehicle: 2014 Toyota Prius v (Mileage: 70,000) Problem Description: The vehicle is experiencing a critical failure of the Electronically Controlled Braking (ECB) system, specifically the Brake Actuator and Booster Pump assembly. The dashboard currently displays multiple warning indicators: ABS light, Traction Control light, and the Brake System Warning light (Master Warning "!"). Symptoms: Mechanical Failure: The internal high-pressure accumulator is failing to hold pressure. The electric brake booster pump is heard cycling (straining) every 10–20 seconds even when the vehicle is stationary and the brake pedal is not depressed. Loss of Braking Safety Features: The system has disabled regenerative braking and Anti-lock Braking (ABS), causing significantly increased stopping distances and a "wooden," unresponsive brake pedal feel. Predictability of Failure: This failure matches the exact symptoms described in Toyota’s Customer Support Program 20TE07 (and previously ZJB), which acknowledges an internal defect in the brake actuator. Safety Risk: The sudden transition from power-assisted braking to manual hydraulic braking during a drive creates an immediate safety hazard. As the pump motor continues to cycle excessively to compensate for the internal leak, it is at risk of total thermal failure, which would lead to a near-total loss of braking assist while the vehicle is in motion. Additional Notes: Despite the vehicle having only 70,000 miles (well under the 150,000-mile limit acknowledged in Toyota’s support programs), Toyota has declined to provide assistance because the vehicle has surpassed the 10-year age mark. I am filing this report because a primary safety component (brakes) should not experience catastrophic internal failure at 70,000 miles, regardless of the vehicle's age.

Filed May 1, 2026 · Brakes · OR

Suddenly Cars Brakes failed with vehicle almost lunged forward. I had to slam the brakes heavily for it to stop; Took the vehicle to Toyota Service and clearly its a QUALITY issue toyota acknowledged as a know problem with error code C1391. They even had customer support program 20TE07 acknowledging it as their issue; I almost got killed for this. The repair costs are abnormally high at 4900$'s putting me a financial burden also and currently unsafe car; Toyota - they literally KNOW THIS ISSUE and still put me at risk. They are refusing any kind of assistance to help too.

Filed Sep 25, 2025 · Brakes · TN

Upon inspection, our mechanic determined that the master cylinder assembly and the actuator assembly require replacement (error code C1391). It is currently available for inspection, but will need to be repaired soon. Our safety and the safety of others is at great risk, because there is impending brake failure if driven and the end result could be catastrophic. On 09/13/25, the BRAKE, TRACTION CONTROL, ABS and ((!)) lights came on about 10 minutes from home. We drove home, parked the car and did not drive it again until we took it to our mechanic on 09/15/25. During this incident, the brakes failed to respond properly, which could have led to a serious accident. We took the car to a local mechanic and repairs are currently pending. The estimated cost for the necessary parts is approx. $3,000 and the labor costs are estimated to be between $1,100 and $2,000. Our local Toyota dealership was also contacted and they confirmed the presence of code C1391. Please reference Toyota Service Bulletin POL18-03, which addresses issues related to the braking system in certain Toyota models, including the Prius V. This bulletin indicates that various brake system-related warning lamps may illuminate due to internal malfunctions within the brake system, and it outlines affected parts that may require replacement. Additionally, please reference Toyota Customer Support Program 20TE07, which provides extended coverage for certain brake system repairs. It is concerning that, despite this well-known, very serious problem, Toyota has not issued a recall. While our vehicle currently has 116,975 miles, we are aware that the warranty period ended 10 years from the first date of use or 150,000 miles. However, this malfunction not only endangers our safety, but also that of other drivers on the road. We urge the federal safety agency to investigate this matter thoroughly and consider the implications for a potential recall for this model, because Toyota is well-aware of this issue.

Filed Jul 24, 2025 · Brakes · CA

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.

Filed Jun 23, 2025 · Brakes · VA

While driving on the interstate I went to slow down to merge and my brakes failed. The following warning lights came on: 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.

Filed May 27, 2025 · Brakes · SC

brake failure during operation due to bad brake booster pump and accumulator.

Filed Jan 17, 2025 · Brakes · CA

The issue is my brakes failed on me all of a sudden. My abs light, traction control light, and brake light came on out of nowhere. Suddenly didn't have brake pressure. Had to pump the brakes a few times before the car would stop. Luckily I didn't hit anything or anyone. I brought the car to Prius specialist and they diagnosed it saying it was the ABS Actuator Pump Assembly and Master Cylinder. They said it is quite common in the 3rd generation of Prius'. I contacted Toyota North America and they said they had a recall on the parts but it ended Dec 31st, 2021. I bought the car in 2022 unknowingly. Was quoted around $4000 to repair it parts and labor. This is a safety issue that should not be limited to time. Luckily I was not on a Freeway or anywhere where I could have done damage. This issue is a hazard to myself and other people on the road. Toyota needs to resolve this.