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

Help with Grinding sound when breaking and lightly when not.

Discussion in 'Prius v Main Forum' started by Integraoligist, Aug 4, 2022.

  1. Integraoligist

    Integraoligist Junior Member

    Joined:
    Oct 9, 2013
    46
    6
    0
    Vehicle:
    2006 Prius
    Model:
    II
    '14 Prius V 150k miles.

    Over the past couple of months a grinding sound has arose when I slow down between 20mph-5mph. You can't really hear it outside with the windows down, but you can in the cabin especially with the windows up and the cabin is quiet. I can even feel the grind in the steering wheel when slowing down to brake and if going left/right at low speed.

    I assumed it was the brakes, but the pads, calipers and slides are all look and work smooth and perfect. The pads were changed about 3000 miles ago so their still brand new.

    Next I thought it must be one of the wheel bearings. So I changed both front wheel bearings. Nope, noise is still there.

    I reversed and got to speed and tried to brake, but the sound is not there when in reverse, just forward.

    Anyone have any idea what else it could be if it's not the brakes or the bearings?

    Thanks all!
     
    #1 Integraoligist, Aug 4, 2022
    Last edited: Aug 4, 2022
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,130
    50,046
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    does it happen with the engine off?
     
    #2 bisco, Aug 4, 2022
  3. Air_Boss

    Air_Boss Senior Member

    Joined:
    Jun 2, 2012
    4,036
    1,110
    0
    Location:
    New Yawk
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Dry CV joints?
     
    #3 Air_Boss, Aug 4, 2022
  4. Integraoligist

    Integraoligist Junior Member

    Joined:
    Oct 9, 2013
    46
    6
    0
    Vehicle:
    2006 Prius
    Model:
    II
    Yes it does
     
    #4 Integraoligist, Aug 4, 2022
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,130
    50,046
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    could something be caught between a pad and rotor?
     
    #5 bisco, Aug 4, 2022
  6. Integraoligist

    Integraoligist Junior Member

    Joined:
    Oct 9, 2013
    46
    6
    0
    Vehicle:
    2006 Prius
    Model:
    II
    To my knowledge bad CV joints would be a clicking and pop sound.... Not this type of grinding?
     
    #6 Integraoligist, Aug 4, 2022
  7. Integraoligist

    Integraoligist Junior Member

    Joined:
    Oct 9, 2013
    46
    6
    0
    Vehicle:
    2006 Prius
    Model:
    II
    No, just removed all the brakes and checked. Their all good
     
    #7 Integraoligist, Aug 4, 2022
    bisco likes this.
  8. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,130
    50,046
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i hate to say it, but maybe it's in the tranny
     
    #8 bisco, Aug 4, 2022
  9. Integraoligist

    Integraoligist Junior Member

    Joined:
    Oct 9, 2013
    46
    6
    0
    Vehicle:
    2006 Prius
    Model:
    II
    If it were the tranny, why would it grind when breaking? Slowing down without the brakes applied you barley hear it... Turning hard left or right at low speeds you can hear it without breaking, which is why I thought it was the bearings.
     
    #9 Integraoligist, Aug 4, 2022
  10. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,130
    50,046
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    hard left or right could be cv joint

    tranny is always regenerating above 6mph foot of the gas, and more so when braking, but turning shouldn't affect it
     
    #10 bisco, Aug 4, 2022
    Tim Jones likes this.
  11. Air_Boss

    Air_Boss Senior Member

    Joined:
    Jun 2, 2012
    4,036
    1,110
    0
    Location:
    New Yawk
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Starts as a grind, evolves to a click or pop, both typically start with lack of lubrication.
     
    #11 Air_Boss, Aug 5, 2022
    Tim Jones and bisco like this.
  12. Integraoligist

    Integraoligist Junior Member

    Joined:
    Oct 9, 2013
    46
    6
    0
    Vehicle:
    2006 Prius
    Model:
    II
    So these would grind more when breaking? Wouldn't they just grind all the time breaking or not?

    And is there a way to test and re-lubricate these or do you need to buy new ones reguardless?
     
    #12 Integraoligist, Aug 5, 2022
  13. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    8,489
    5,056
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    A cv joint could make noise when braking, not when breaking. Breaking would be the clicking sound. Possible struts or front end parts like ball joints. A front end shop could diagnose. You buy new axle(s) with cv joints if needed.
     
    #13 rjparker, Aug 5, 2022
    Last edited: Aug 5, 2022
  14. Air_Boss

    Air_Boss Senior Member

    Joined:
    Jun 2, 2012
    4,036
    1,110
    0
    Location:
    New Yawk
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    The grind (later, click or pop) occurs when mechanically braked wheels retard the motion of the CV and linked transaxle. When regenerative braking occurs at higher speeds, it is the transaxle doing the braking, not the wheels.

    These CVs are sealed, so not easily re-lubricated.
     
    #14 Air_Boss, Aug 5, 2022
    Tim Jones likes this.
  15. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,130
    50,046
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    at 150k, would it be more likely a cracked boot?
     
    #15 bisco, Aug 5, 2022
(You must log in or sign up to post here.)