1. Welcome to 4Runners.com!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all 4Runner discussion topics
    • Transfer over your build thread from a different forum to this one
    • Communicate privately with other 4Runner owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Different calipers with smaller bolt, can't find info

Discussion in '5th Gen 4Runners (2010-2024)' started by Markhoh3, Jun 11, 2023.

  1. Jun 11, 2023 at 1:52 PM
    #1
    Markhoh3

    Markhoh3 [OP] New Member

    Joined:
    Jun 11, 2023
    Member:
    #33368
    Messages:
    1
    Gender:
    Male
    Vehicle:
    2015 4Runner
    In the process of changing front brakes. New calipers are different than the front, just by the bolt that holds calipers. Mine are 19mm. Replacements are 17mm. Everything that I find at the auto store show small hole 17mm. There is a before and after date of 6/15. What am I missing. Can’t find any information.
     
  2. Jun 11, 2023 at 6:50 PM
    #2
    Startrek

    Startrek New Member

    Joined:
    Apr 28, 2021
    Member:
    #21187
    Messages:
    362
    Gender:
    Male
    Vehicle:
    2012
    I am bored. are you sure new calipers direct replacement of original. what are you ordered and from what supplier. you should be able to re-use original bolts. why are you changing calipers. do you know how to bleed brakes on 4Runner. if you having troubles already - don't do it.
     
  3. Jun 13, 2023 at 10:02 AM
    #3
    morfdq

    morfdq New Member

    Joined:
    May 25, 2022
    Member:
    #27196
    Messages:
    483
    Gender:
    Male
    First Name:
    Derek
    Vehicle:
    2022 SR5 Premium
    TRD Wheels, exhaust and skid plate
    my thought exactly. Why are you replacing the calipers? Calipers very seldom fail. VERY SELDOM. in my 30+ years of working on cars, ive replaced calipers maybe 5 times.
     
    steelevo likes this.
  4. Jun 13, 2023 at 10:16 AM
    #4
    steelevo

    steelevo Not so new anymore...

    Joined:
    Nov 29, 2022
    Member:
    #29845
    Messages:
    2,432
    Utah
    Vehicle:
    2023 4Runner TRD Pro Solar Octane
    Exactly this.

    Don’t be a parts swapper and diagnose the issue properly. Auto part stores don’t always give you the correct parts. Their catalog may have incorrect information and can cross reference the wrong part. Always double check your part at the store, or bring the old part with you.
     
  5. Jun 13, 2023 at 10:20 AM
    #5
    krashDH

    krashDH New Member

    Joined:
    May 24, 2023
    Member:
    #33058
    Messages:
    87
    Gender:
    Male
    Vehicle:
    2016 SR5, 4WD
    It's not just about the caliper "failing" that you have to replace the calipers. If you've ever lived in a harsh environment, pistons FREEZE into the calipers...corrosion basically welds them to the bore of the caliper. Then they don't move and they can destroy the disk because they won't retract. If you can't free the pistons conventionally, you'll destroy the bore most likely trying non-conventional ways to break them free. I've rebuilt many calipers in my day, as well as replaced them.

    The 4runner we just got had this issue. Frozen pistons in 3 of the 4 calipers (both rears and driver side fronts). I could not pop any of the frozen pistons free and I tried all the tricks I've used of the years. None would budge. When I had these apart, I looked at the seals and noticed that these OEM seals were some of the flimsiest I've seen. The "snap ring" that holds the seals in place in the front could easily bend and then you're letting in moisture. So it was time to replace the calipers at this point. I was able to find 2 new OEM fronts and 2 OEM remans. Don't mess with aftermarket remans ever.

    To the OP, your question/post doesn't really make sense. The bolt diameter for the fronts is 14mm...so not sure what you're measuring. If you're using the head socket size, that's not correct and this can vary between bolt diameter. But the fronts OEM bolt is 14mm. I've read floating around there's a 12mm bolted version too, but I can't verify that. Maybe that's the 2WD version? Either way, the majority of the front bolts and receiving holes will be for a 14mm bolt
     
  6. Jun 13, 2023 at 1:00 PM
    #6
    08TXRunner

    08TXRunner New Member

    Joined:
    Feb 17, 2020
    Member:
    #13179
    Messages:
    925
    Gender:
    Male
    Vehicle:
    '20 SR5P
    Frozen pistons was a big problem with the 4th gen.
     
    krashDH[QUOTED] likes this.
  7. Jun 13, 2023 at 2:11 PM
    #7
    krashDH

    krashDH New Member

    Joined:
    May 24, 2023
    Member:
    #33058
    Messages:
    87
    Gender:
    Male
    Vehicle:
    2016 SR5, 4WD
    This 2016 is the first 4runner I've worked on since I personally owned a 99 Tacoma back in the day.
     
  8. Aug 20, 2023 at 5:45 AM
    #8
    Sweeprider

    Sweeprider New Member

    Joined:
    Aug 20, 2023
    Member:
    #35024
    Messages:
    2
    Gender:
    Male
    Vehicle:
    2017 Black 4Runner rustbucket
    I have a 2017 in upstate NY and it is a rust-bucket. All calipers are frozen. I replaced the rear, but the fronts have 19mm caliper
    mounting bolts and everything I find has either 14mm or 17mm. So Markhole3 is correct. The auto parts stores keep giving me the
    wrong calipers. Now I bring a mounting bolt with me to try fitting in the hole. No luck so far.
     
  9. Aug 20, 2023 at 5:51 AM
    #9
    Sweeprider

    Sweeprider New Member

    Joined:
    Aug 20, 2023
    Member:
    #35024
    Messages:
    2
    Gender:
    Male
    Vehicle:
    2017 Black 4Runner rustbucket
    I believe the changeover from 17mm to 19mm front caliper mounting bolts occurred in 2015, but not positive on the year.
     
  10. Sep 16, 2023 at 3:24 PM
    #10
    15runnerguy

    15runnerguy New Member

    Joined:
    Sep 16, 2023
    Member:
    #35708
    Messages:
    2
    Gender:
    Male
    First Name:
    Jason
    Vehicle:
    2015 SR5
    2” spacer lift 285/70-17 TRD wheels
    Yea the change was in mid-year 2015. I’m going through it now. Went to parts store gave me calipers with 12mm bolt holes. Mine has 14mm bolt mounting holes. So going back to Toyota Monday and but the proper ones. I’ve heard part stores are junk for Toyota parts but I was just hoping to get it done today to get me by for a bit until I could get up to Toyota where I used to work. They treat me good there
     

Products Discussed in

To Top