2014 Toyota Prius · symptom sheet
Brake pedal goes hard or the booster or vacuum pump fails
- 47owner reports
- 120,000median miles
- $3,100median quote
- 0involved a crash
Newest report Sep 4, 2026 · checked Sep 29, 2026
47 of the 96 reports of brake wear on the 2014 Prius describe brake booster failure.
Part of Brakes grind, pulse or wear early (96 reports) · also: ABS light on, brake light on
Tick what matches of 47 reports
Brake booster failure on other Prius years
Report counts are for each model year on its own, so a newer car has had less time to collect them. Model years with too few reports of it for a sheet: 2016.
What this problem usually is
This is the narrower sheet inside brakes for reports about a hard pedal or a failed power assist. The pedal stops feeling normal: it turns stiff, takes far more force, and the car needs a longer distance to stop.
What got replaced
Owners who name the part that was replaced mention the brake booster (44 reports) and the master cylinder (12 reports).
Recalls and investigations
No recall on the brakes covers the 2014 model year as of Sep 29, 2026.
NHTSA investigations into the brakes on the Prius
Brake actuator valve wear. Open.
Brake actuator valve wear. Closed jan 21, 2021.
Braking performance, hybrid vehicle. Closed jul 12, 2010.
What owners paid
20 of the 47 reports quote a price. Each dot is one quote. The middle half runs $3,000 to $4,000.
When it happens
The middle half of failures fell between 92,000 and 150,000 miles, from the 22 reports that gave a mileage.
Is this a known problem?
The manufacturer has sent NHTSA 2 service bulletins or notices for the 2014 Toyota Prius that deal with this problem. Newest first.
Federal rules make a manufacturer send NHTSA a copy of any notice about a defect that goes to more than one dealer or owner. Most of these are service bulletins, the repair instructions manufacturers send to dealers. NHTSA generally leaves safety recall bulletins out of this file, and recalls are listed separately.
Dealer Package: Toyota has received reports about certain internal malfunctions of the brake booster assemblies in some of the subject vehicles.
Dealer Letter: March 7, 2019 ZJB Phase 2 Launch for Certain 2011 ? 2015 Model Year Prius Vehicles and Certain 2012 ? 2015 Model Year Prius PHV vehicles.
What owners wrote
“The brake booster assist assembly failed, causing a leak of brake fluid, im told that over time this failure can lead to a break failure. I contacted Toyota. They informed me that there was an assistance program for fixing this defect. However it expired in 2024? If they know about a defect why did the program expire? This is a safety issue.”
Filed Apr 4, 2025
“Failed Brake booster and pump assembly, confirmed by Toyota service. Warning lights turned on all at once: AEB, skid control and brake light. Estimated cost to repair is $3,000.”
Filed Mar 22, 2025
“Failed brake booster on 2014 Toyota Prius due to Customer Support Program Bulletin POL18-03 See attached documents sent to Toyota. They would not reimburse the ~ $3,000 repair to the brake booster which was in the Customer Support Program Bulletin POL18-03 Almost had an accident and the repair was done within the repair window.”
Filed Feb 6, 2025
“Got code C1391, a common issue with the Prius. Brake Booster Assembly is defective due in no part to owner/driver of vehicle. This creates a serious safety issue with braking. Traction control light, brake light, and ABC light are all on and repair is ridiculously expensive.”
Filed Jan 9, 2025
Should you keep driving it?
This page can't tell you that. 0 of 47 reports involved a crash. Owners who file are the ones who had a bad experience, and nobody checks their reports. If the problem affects steering, braking, power or a fire risk, treat it as a safety fault and have it inspected before a long or high-speed drive.
File your own report with NHTSA. Complaint counts are how a problem gets an investigation. How reports land on this sheet.
Guide Taking it to a shop? How to describe this problem so it gets found