1. Attachments are working again! Check out this thread for more details and to report any other bugs.

2015 Prius Brake Booster/Actuator Questions

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by 15SuperPrius, Nov 13, 2022.

  1. 15SuperPrius

    15SuperPrius Member

    Joined:
    May 18, 2019
    174
    65
    0
    Location:
    FL
    Vehicle:
    2015 Prius
    Model:
    Two
    Hi folks,

    As of recent I've noticed that the brake actuator on my car makes the pressurizing sound every 10-12 seconds constantly during driving, and continues to do so for a few minutes after the car has been turned off; this is accompanied by a spongy brake pedal that allows me to peg it to the floor if I apply enough force. I believe brake actuator failure is a well-known problem on the 3rd gen Prius, and based on what I've read, the car qualifies for a free replacement as long as it has under 150k miles and the in-service date was less than 10 years ago. Is this correct information? If so, the fix should be covered by Toyota given that my career meets the criteria.

    I checked the brake fluid level and it is slightly under the middle/normal line (pretty much in the center between the min and max lines) eliminating the possibility of a leak. I believe the actuator likely has an internal pressure leak, leading to the spongy brake pedal and the constant actuator sound every 10-12 seconds.

    Thanks!
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,144
    50,053
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    you can pull up the warranty extension at toyota.com/owners to see if you need a trouble code to qualify, or just check with dealer service
     
  3. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,910
    16,213
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Do you have any brake-related warning lights yet?

    I think you've got the right diagnosis by the sounds, but for eligibility under the ZJB customer support program, one of four specific trouble codes should be showing. Probably that won't take long at this point.