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

Grinding noise and grooves in front brake discs

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Nate_F, Dec 30, 2016.

  1. Nate_F

    Nate_F Junior Member

    Joined:
    Dec 30, 2016
    25
    7
    0
    Location:
    Idaho
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    I've been noticing grinding coming from the brakes recently in my 60k-mile 2012 Prius 3. I read that there is a known rear brake problem but my vin didn't match any known issues in the Toyota Recal and Service Campaign page.

    To me, it sounds like the general grinding noise is coming from the front. The pics below seem to correlate.

    Any thoughts? Why are both front discs grooved while both rear discs are smooth? I haven't had it serviced yet and wanted to gather some information first.


    Front (both passenger and driver sides are grooved. Haven't seen the inward facing side yet):
    [​IMG]


    Rear (both passenger and driver sides are smooth. Haven't seen the inward facing side yet):
    [​IMG]


    From farther away (front):
    [​IMG]

    From farther away (rear):
    [​IMG]
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    When did you last have a brake maintenance? The US interval for thorough brake inspection is 3 year or 30K miles.
     
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    the front brakes do more work i believe. not sure why so much grooving, how much left on the pads?
     
  4. Tande

    Tande Active Member

    Joined:
    Jan 29, 2006
    497
    299
    0
    Location:
    Mich.
    Vehicle:
    2017 Prius
    Model:
    II
    IMHO.....something not "Normal" going on.......especially at 60k......got a 100k on mine & they look like they're good for another 100k......FWIW
     
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    some have shown early wear due to corrosion and lack of attention to inspection and lubrication, as mendel mentions above.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Yeah I'm speculating caliper pin lube has dried up, not allowing the caliper to float; that the brakes have never been opened up.

    If it's messed up enough a preemptive set of fresh pads, clean-and-lube of all contact points and the pins, and removal-and-burnish of the rotor might solve. If wear is uneven, they'le likely be noisy for the next week, till they settle down.
     
    bisco likes this.
  7. Tande

    Tande Active Member

    Joined:
    Jan 29, 2006
    497
    299
    0
    Location:
    Mich.
    Vehicle:
    2017 Prius
    Model:
    II
    My bad......I was ASSUMING proper maintenance.......I do know better.....:ROFLMAO:
     
    bisco likes this.
  8. Nate_F

    Nate_F Junior Member

    Joined:
    Dec 30, 2016
    25
    7
    0
    Location:
    Idaho
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    There's no maintenance required at 60k for the brakes (just inspection).

    A tech just told me he used brake cleaner on the discs and stomped the brakes a bit an the grinding noise is apparently gone now. Pads are at 50% in the front and 60% in the back. He said the grooves weren't out of normal and were probably caused by rust buildup.

    Doesn't make much sense to me to see grooves like this.
     
  9. Nate_F

    Nate_F Junior Member

    Joined:
    Dec 30, 2016
    25
    7
    0
    Location:
    Idaho
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    I don't fully understand it, but the rotors are much smoother to the touch now. Pad-colored rust bands maybe?
     
  10. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Maintenance, inspection, don't get muddled with the language.

    Every 5000 miles or 6 months they're to be "visually inspected", and every 3 years or 30K miles is the in-depth inspection (aka "maintenance"). Whatever it's called, the calipers are supposed to be pulled, calilper pins lubed, pads/shims cleaned and inspected, contact points cleaned and lubed, disc thickness/runout checked to be within specs.

    Check your Warranty and Maintenance Manual.
     
  11. Nate_F

    Nate_F Junior Member

    Joined:
    Dec 30, 2016
    25
    7
    0
    Location:
    Idaho
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Interesting. Those points are not mentioned in the 2012 Toyota Prius Warranty and Maintenance Guide.
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    First instance page 41.

    It's your car. If the dealership has convinced you it has miracle brakes, what can I say.
     
  13. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    the whole car is almost a miracle.
     
    Montgomery likes this.
  14. Nate_F

    Nate_F Junior Member

    Joined:
    Dec 30, 2016
    25
    7
    0
    Location:
    Idaho
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Nope.

    I never said that. I mentioned trends which another user on this forum agreed with. Also, the results in this case were that the brakes and discs were fine (it was just gunk build-up).

    lol
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Have you ever had the calipers off? All the chest beating aside, I'm thinking it's the caliper pins drying up. With 60K on the odometer you should have had the in-depth service (aka inspection, aka maintenance) twice now: every 3 years or 30K miles.

    One thing, Toyota documentation is poor, shows the soup-to-nuts breakdown of the brakes, doesn't differentiate well: visual inspection, vs complete maintenance, vs complete caliper overhaul. Honda is better in this regard: their Shop Manual have specific section, say brake service, and walk you step-by-step through what's required.

    Still, this stuff is pretty much biblical, never changes.
     

    Attached Files:

    #15 Mendel Leisk, Jan 5, 2017
    Last edited: Jan 5, 2017
    Montgomery likes this.
  16. Nate_F

    Nate_F Junior Member

    Joined:
    Dec 30, 2016
    25
    7
    0
    Location:
    Idaho
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    That makes sense.

    I'll try and take a look at the pins when it's not 0 degrees here. The place I took it too wasn't very specific on what they did with their "Brake Check" other than they measured the pad thickness so I don't know if they even took the caliper off.
     
    Mendel Leisk likes this.
  17. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Zero Fahrenheit? Ouch! It's been stubbornly below freezing here in lower mainland BC, not like that though.

    I'm gonna do our front brakes come spring, when taking the snows off.

    If you DIY it's safest to disconnect 12 volt negative cable and isolate it, before opening anything up. Before reconnecting when everything is reassembled , push brake pedal multiple times. This avoids possility of car detecting excessive pedal travel, throwing a code.
     
    Raytheeagle likes this.