2013 Toyota Prius: soft or spongy brake pedal

Filed Oct 19, 2026 · Brakes · CA

On XXX, at approximately 152,570 miles, the brake, ABS, and traction-control warning lights illuminated at the same time on my 2013 Toyota Prius. The brakes felt spongy, and I heard a recurring buzzing sound approximately every 3 seconds. Because of the change in brake-pedal feel and concerns about braking safety, I stopped using the vehicle. I reported the problem to Longo Toyota in [XXX], which directed me to Toyota customer support. The vehicle was subsequently diagnosed with trouble code C1391, “Internal Leak in Accumulator.” I contacted the dealership and Toyota customer support about Customer Support Program ZJB, which addressed code C1391 brake booster and brake booster pump failures. Toyota denied coverage because the failure occurred outside the program’s time and mileage limits. The symptoms began only 2,570 miles beyond the 150,000-mile limit. My primary concern is **safety**, not simply the expiration of coverage. The vehicle developed spongy brakes, multiple warning lights, and frequent buzzing. The diagnosis appears consistent with the type of brake-system failure Toyota previously addressed through ZJB. I request that the federal safety agency investigate whether this condition constitutes a safety defect affecting 2013 Toyota Prius vehicles and whether a recall or other corrective action is warranted, including for vehicles that develop the failure after the support program expires. I can provide the diagnostic report and available supporting records. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 8, 2026 · Brakes · CA

While driving my 2013 Toyota Prius, the red brake warning light, traction control, and ABS warning light suddenly illuminated on the dashboard. The brake pedal became spongy and required significantly more effort to stop the vehicle, indicating reduced braking power. The vehicle was diagnosed with code C1391 — abnormal leak in the brake booster accumulator assembly — a known manufacturing defect acknowledged by Toyota via Customer Support Program bulletin ZG1 for 2010–2015 Prius vehicles. The brake accumulator was replaced by a repair shop (ARC Auto Repair, Pasadena, CA), but the issue has recurred. The symptom is pressure-dependent: brake performance degrades in Eco drive mode as accumulator pressure bleeds down, and partially restores in Power mode when the system is forced to repressurize. Toyota dealership (Hamer Toyota, Mission Hills, CA) and Toyota Customer Experience (1‑800‑331‑4331) both declined to assist, citing expired warranty. This is a known safety-critical defect in the braking system that Toyota has previously acknowledged. No crash or injury occurred, but the reduced braking capability presents a significant safety risk to the driver and public.

Filed Mar 4, 2026 · Brakes · TX

This is the 3rd time I have had to address this issue. The ABS system fails, resulting in increased braking distances. The dealership refuses to warranty or recall this dangerous defect, replacing the parts which fail again. Symptoms include increased braking distance, extremely hard pedal, lack of ABS function, lack of traction control, lack of hybrid regen. The entire dash lights up with indicators for all these functions.

Filed Jan 12, 2026 · Brakes · SC

I was driving on Saturday January 10th, 2026, when out of nowhere all of my dash warning lights came on and the brakes felt spongy and unresponsive. I had to limp home with 20% of my brake capacity which was very scary. Did some research and it was my brake actuator that went out. Dealer quoted me $4,000 to fix! This is a very common issue with Priuses between 2005-2015 and it's a crime that the part has NOT been recalled. Please put out a recall for this part. Toyota has already had a class-action lawsuit so precedent has been set. I have no idea how I'm going to pay $4,000 to fix this, I'm recently unemployed. Please hold Toyota liable!

Filed Nov 3, 2025 · Brakes · IA

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.

Filed Aug 24, 2025 · Brakes · CA

Car currently at 88k miles. Spongy and weakening brake pressure. Slower to stop. Brake constantly priming indicates brake actuator and brake boost failure. Confirmed by independent mechanic.

Filed Aug 20, 2025 · Brakes · OR

When I’ve hit a pothole or hit the breaks to hard by ABS, and traction control lights would come on and then turn off. The other day they all turned on and stayed on with the break light on as well. Breaks all seemed to work fine, just a little spongy. I brought it in to a shop and they estimated 3k to repair Remove, replace, calibrate, and bleed ABS accumulator assembly and brake master cylinder assembly. Test drive-New OEM Toyota Parts. These parts were recalled but only up to 10 years or 150k miles. I’m at 164k so ineligible for the recall but if this part completely failed while I was driving I could have been killed or caused someone serious harm.

Filed Mar 26, 2023 · Brakes · CA

Symptom: Brake pedal felt spongy with multiple dash warning lights ON and booster pump cycling on/off. Safety Risk: yes, my Prius felt like it wasn’t stopping properly. My family and vehicles around were put at risk. Problem Confirmation: the problem has reproduced and has been confirmed by a local Toyota dealer. DTC: C1391 Warning lamps: there is multiple lamps On: Brake, ABS, trac/vsc, “!” There is a Toyota Customer Support Program(CSP) : Prius Brake Booster Pump and Brake Master Actuator CSP ZJB. I also reached out to Toyota and I was told the repair would not be covered due to mileage but was within the 10 year “use of date”. (10 year or 150,000 miles) My Toyota case number is: 230324001393

Filed Jun 20, 2020 · Brakes · IL

My brakes don't work like they normally do. They are hard and the brake pedal is spongy. The traction control, ABS, brake and a round with an exclamation pint light is on. It goes away and it comes back and its very dangerous because it happens when I'm driving and once I try to stop the brake pedal is hard. First time it happened I almost hit a car infant of me at a stop light.