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

2013 Prius Brake actuator/pump issues - is DOT4 Brake Fluid an easy fix for this problem?

Discussion in 'Gen 3 Prius Technical Discussion' started by Yerbluez, Dec 29, 2021.

  1. Yerbluez

    Yerbluez Junior Member

    Joined:
    Mar 8, 2020
    13
    1
    0
    Location:
    Virginia
    Vehicle:
    2013 Prius
    Model:
    Three
    Hoping someone can make a suggestion as to what I should do to avoid a $4k brake master cylinder repair job. I've searched this sub already but can't seem to find an agreement on what to do. I have a 2013 Prius and the ABS brake pump (I'm assuming) is starting to turn on way too frequently. I have read that this can eventually lead to a failure of components of the brake system and a new master cylinder is required.

    Is there any somewhat inexpensive fix I can do now to prevent this from getting worse? I read someone had luck changing the brake fluid to DOT4 and it seemed to fix the issue. If there is no reasonable fix and this isn't covered by a recall then I may have to look into selling my beloved Prius. 3-4k is too much money to spend on this car. Does anyone else have any recent experiences with this?

    Thanks in advance!
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    there may be an extended warranty, but you need a trouble light/code.

    i've read that changing the fluid can sometimes help reduce noises in the valves, but nothing about repairing leaks.
     
  3. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,064
    14,970
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    That's probably getting the cause and effect shuffled a little bit.

    Failure of components inside the master cylinder assembly is most likely the reason your pump is cycling so frequently. (By the way, how frequently is "frequently"? If the leaking is fast enough, you can probably hear it with a mechanics' stethoscope, and know for sure which of the two assemblies the leak is in.)

    So it is probably too late to find a way to not need the actuator assembly.

    It might be possible, though, to get that sorted before the pump has also been worn out from having to run so often, and at least avoid having to replace both. (On top of being more money in parts, that would be more labor; access to the pump is a bear.)
     
  4. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    7,471
    4,372
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Doing a brake flush can fix it for a few days by eliminating nitrogen or air in the lines. Then it will return.
     
    Tim Jones likes this.
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,463
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Repair of failing brake components (I won't even attempt to name those components) aside, the spec'd fluid is DOT3. Also, while Toyota USA says nothing on the subject, Toyota Canada says to replacef the fluid tri-yearly or 48K kms, whichever comes first.
     
    Tim Jones likes this.