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

Normal noise from brake master cylinder/ABS unit?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by phobix, Apr 19, 2014.

Page 1 of 2
  1. phobix

    phobix Junior Member

    Joined:
    Apr 7, 2012
    22
    5
    0
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A
    Hello Everyone,

    I have leased my 2012 prius since April 2012 and about a year ago I began to notice the following noise originating from the master cylinder/ABS unit. The noise happens if I push the pedal firmly to the floor and occasionally during regular braking. The braking system seems to be working fine and regen braking is functional. I am wondering if this noise is a sign of an imminent failure. The reason I am asking is because I just decided to buy back the prius off lease and I still have factory bumper to bumper warranty available and have heard horror stories concerning the cost of a replacement ABS unit on the Gen III Prius.

    Listen to audio recording

    Video version here:
    WeVideo

    Thanks in advance
     
    #1 phobix, Apr 19, 2014
  2. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,817
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    I believe there is a TSB for that. Someone will come along shortly and point it to you. Or search.
     
    #2 edthefox5, Apr 19, 2014
    phobix likes this.
  3. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,525
    8,428
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    This sound you are describing is brake actuator noise, all prius cars make this sound. If there is a problem, you would have a dtc or dash light to warn you the system has a fault.

    The was a recall on early 2010 models to replace the brake booster, but no recall on 2012 models

    SM-N900P ?
     
    #3 JC91006, Apr 19, 2014
    phobix likes this.
  4. phobix

    phobix Junior Member

    Joined:
    Apr 7, 2012
    22
    5
    0
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A

    This is certainly reassuring to hear that this is a normal noise. Did you actually listen to the recording? I used my iphone and had it placed adjacent to the ABS unit while my wife was pushing on the brake pedal.
     
    #4 phobix, Apr 19, 2014
  5. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,525
    8,428
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    I was going by your description only, I need a computer to hear the sound.

    SM-N900P ?
     
    #5 JC91006, Apr 19, 2014
  6. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,817
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Went to listen to it but requires a download. No thanks.
     
    #6 edthefox5, Apr 19, 2014
  7. phobix

    phobix Junior Member

    Joined:
    Apr 7, 2012
    22
    5
    0
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A
    As an IT professional I should know better, I completely understand your concern. I will embed a YouTube version of the audio clip a little later this evening. Thanks for your input
     
    #7 phobix, Apr 19, 2014
    edthefox5 likes this.
  8. PriusInParadise

    PriusInParadise Member

    Joined:
    May 24, 2012
    180
    91
    0
    Location:
    Hawaii
    Vehicle:
    2011 Prius
    Model:
    Two
    It is the normal sound of the brake hydraulic pump. The pump runs as needed to maintain hydraulic pressure in the brake accumulator. Depressing and releasing the brake pedal will make the pump run, as will normal braking. It will not do it on every application, but only when needed to maintain pressure.

    The hydraulic pump will also run when first opening the driver's door after being parked for several hours.

    If you hear this repeatedly while in Ready mode, without depressing the brake pedal, there may be a problem.
    Some Gen II's and Camry Hybrids are experiencing internal pressure bleed-down in the brake accumulator that causes the pump to run every 20 seconds or so.
     
    #8 PriusInParadise, Apr 19, 2014
  9. phobix

    phobix Junior Member

    Joined:
    Apr 7, 2012
    22
    5
    0
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A
    Hopefully this is acceptable for those of you with reservations on downloading, I am struggling at the moment in trying to edit a video using chromebook.
     
    #9 phobix, Apr 19, 2014
  10. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,817
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    He's not referring to the rattle snake sound of the brake vacuum pump is he? Never listened to his sound post.
    The car always made that sound.
     
    #10 edthefox5, Apr 19, 2014
  11. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,525
    8,428
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    Would this pose a possible safety risk? Another recall coming?


    SM-N900P ?
     
    #11 JC91006, Apr 19, 2014
    phobix likes this.
  12. phobix

    phobix Junior Member

    Joined:
    Apr 7, 2012
    22
    5
    0
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A
    .
    Thank you for the clear explanation, makes absolute sense. Fortunately, I am not hearing this sound repeatedly.
     
    #12 phobix, Apr 19, 2014
  13. phobix

    phobix Junior Member

    Joined:
    Apr 7, 2012
    22
    5
    0
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A
    For those of you who do not want to download the file I have posted a video here:

    WeVideo
     
    #13 phobix, Apr 19, 2014
  14. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,525
    8,428
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    That sound is not normal, I would have it addressed under warranty before it runs out

    SM-N900P ?
     
    #14 JC91006, Apr 19, 2014
  15. phobix

    phobix Junior Member

    Joined:
    Apr 7, 2012
    22
    5
    0
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A

    It didn't sound right to me either. Presumably you have never heard this sound from your own Gen III prius?
     
    #15 phobix, Apr 19, 2014
  16. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,525
    8,428
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    Never heard that sound, sounds alarming

    SM-N900P ?
     
    #16 JC91006, Apr 19, 2014
  17. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,817
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    That may be the pump normal sound just recorded in a weird angle. Where is the mic being placed to record that?
     
    #17 edthefox5, Apr 19, 2014
  18. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,817
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    And why is there an abs pump on the ground there lol. Did you find someone with that weird sound too?
     
    #18 edthefox5, Apr 19, 2014
  19. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,817
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Whatever it is should be covered under 3/36 though. Hopefully you have less than 36,000 miles :eek:
    Take it in asap so it doesn't leave you on the side of the road.
     
    #19 edthefox5, Apr 19, 2014
  20. phobix

    phobix Junior Member

    Joined:
    Apr 7, 2012
    22
    5
    0
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A

    The mic was roughly roughly 3 inches away from the ABS unit. I had my wife depress the brake pedal to reproduce the problem while I had the hood open. This same sound is audible from the cabin albeit a little less pronounced.
     
    #20 phobix, Apr 19, 2014
(You must log in or sign up to post here.)
Page 1 of 2