1. Welcome to Tundras.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 Tundra discussion topics
    • Transfer over your build thread from a different forum to this one
    • Communicate privately with other Tundra owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Coolant Leak - Bypass pipe O-ring

Discussion in '1st Gen Tundras (2000-2006)' started by jerryallday, Jan 10, 2021.

  1. Jan 10, 2021 at 12:34 AM
    #1
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    I had mystery leak and was finding coolant where the transmission and engine meet. Turns out it was a bypass pipe o-ring that connect to the back of the water pump.

    Changing all the gaskets and o-rings just incase. Doing the water pump just because everything is out of the way. Timing belt was changed at 100k in 2013 @ 160k now (the belt came in the kit, might change also)
    [​IMG]

    Anyways found this repair/ service
    Manual online thought I’d share. For 2005-2006 Tundra
    https://drive.google.com/file/d/0B-5MhfqaHsHObmt6RDVhOGtKWjA/view
     
  2. Jan 10, 2021 at 6:04 AM
    #2
    Professional Hand Model

    Professional Hand Model A.K.A ‘Golden Hands’

    Joined:
    Apr 29, 2018
    Member:
    #14878
    Messages:
    15,007
    Gender:
    Male
    First Name:
    Fred
    ‘Somewhere’... a State of Mind
    Vehicle:
    2002 Tundra SR5 4WD 4.7L AC Silver Metallica
    Hand Protectors
    Nice work doing it all while its open. Do you have a pic of the leaky O-ring Connection? We have a few members come through here with that same Coolant Symptom at the Engine/Tranny spot.
     
    Doris01TRD likes this.
  3. Jan 10, 2021 at 8:07 AM
    #3
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    Below is a photo of what the leak looked like. It leaks here because the coolant leaks within the engine valley and the block has two holes on the back like a gutter.

    Here is the video I found explaining it way better. https://www.youtube.com/watch?v=6fx5hFQHUKI

    Below is a photo from under the car, where it was leaking. (Engine meets the trans)
    [​IMG]

    Below is what the bypass pipe looks like, you can see little no O-ring left. This O-ring connects behind the water pump.
    [​IMG]

    One thing I didn't do that I regret was not doing a pressure test before draining the coolant. This would have allowed me to see everywhere it was leaking because I had the head off. So now I am replacing every gasket and o-ring.
    [​IMG]

    Will update you later this week since I am waiting on parts.
     
    Last edited: May 14, 2021
  4. Jan 10, 2021 at 9:15 AM
    #4
    Professional Hand Model

    Professional Hand Model A.K.A ‘Golden Hands’

    Joined:
    Apr 29, 2018
    Member:
    #14878
    Messages:
    15,007
    Gender:
    Male
    First Name:
    Fred
    ‘Somewhere’... a State of Mind
    Vehicle:
    2002 Tundra SR5 4WD 4.7L AC Silver Metallica
    Hand Protectors
    Thanks. I’m trying to remember, but I think that O-Ring (the small one which failed you) is suppose to be replaced during the Timing Belt Change. Trying to remember if I did mine? Maybe yours was skipped last time?

    I remember 2 O-Rings large and a small.
     
  5. Jan 10, 2021 at 10:03 AM
    #5
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    Yes, those two O-rings come in the water pump/ timing kit. I don’t think they changed the back one (small bypass pipe) back in 2013.
     
  6. Jan 10, 2021 at 10:10 AM
    #6
    Darkness

    Darkness Allergic to white

    Joined:
    Jul 23, 2018
    Member:
    #17315
    Messages:
    9,976
    Gender:
    Male
    First Name:
    Luis
    All over SoCal
    Vehicle:
    The darkest
    It's really dark
    Amazing how much work an o ring can cause. Good job finding and fixing that.
     
  7. Feb 7, 2022 at 9:40 PM
    #7
    andyman0369

    andyman0369 New Member

    Joined:
    Feb 7, 2022
    Member:
    #74283
    Messages:
    5
    Gender:
    Male
    Nashville
    '02 Limited 2UZ-FE 189k.
    Similar problem after completing a timing belt swap. What a pure joy to discover a leak as I was all done and about to reinstall the lower splash guards... Noticed the coolant overflow container level kept dropping...

    Changed timing belt, water pump [AISIN TKT-021 kit], serpentine tensioner, Idler pulley, fan pulley bracket, accessory drive belt, coolant drain & fill, spark plugs - all new & OEM replaced.

    Can't find P/Ns for this O-ring and [water neck(?)] thermostat housing O-ring. Anyone have the P/Ns or specs for these rings?
     
    Doris01TRD likes this.
  8. Feb 7, 2022 at 11:51 PM
    #8
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    Can you add photos of what you need part numbers for ?
     
  9. Feb 8, 2022 at 1:35 AM
    #9
    NickB_01TRD

    NickB_01TRD You don't need less cars, just more driveway.

    Joined:
    Jun 16, 2021
    Member:
    #64346
    Messages:
    2,080
    Gender:
    Male
    First Name:
    Nick
    KY
    Vehicle:
    01 Tundra V8 4X4 AC SR5 TRD
    I'm assuming he's talking about the O-Rings that are included in the timing belt kit. Maybe implying that his ripped or weren't included in the kit he used and now all he needs is the O-Rings separate of the timing belt kit.
    Just a guess.
    This is the PN for the thermostat gasket that I used on mine. Amazon says it doesn't fit for whatever reason.
    16346-50010, Engine Coolant Thermostat Gasket
     
  10. Feb 8, 2022 at 4:26 AM
    #10
    bmf4069

    bmf4069 Yup, that's car parts in a dishwasher

    Joined:
    Sep 1, 2018
    Member:
    #18880
    Messages:
    7,148
    Gender:
    Male
    TX
    Vehicle:
    02 AC sr5 4wd v8
  11. Feb 8, 2022 at 7:15 AM
    #11
    andyman0369

    andyman0369 New Member

    Joined:
    Feb 7, 2022
    Member:
    #74283
    Messages:
    5
    Gender:
    Male
    Nashville
    Thanks NickB_01TRD and bmf4069 for your responses.

    I've copied the pic from OP showing the locations of the two o-rings I need. Small one for the bypass tube and larger one for the water neck.

    BMF is spot-on about the two o-rings from the TKT-021 kit. Thanks for the link to the thermostat gasket but that's not what I need. Should be something easy to find, I'm just ridin' the struggle bus here...

    Thanks in advance, I love the community resources here!

    [​IMG]
     
    NickB_01TRD and jerryallday[OP] like this.
  12. Feb 8, 2022 at 8:09 AM
    #12
    andyman0369

    andyman0369 New Member

    Joined:
    Feb 7, 2022
    Member:
    #74283
    Messages:
    5
    Gender:
    Male
    Nashville
    By george, I got It!

    For anyone else looking:

    Bypass Pipe O-Ring - 96761-24019
    Water Neck O-Ring - 96761-35035
     
    jerryallday[OP] and FrenchToasty like this.
  13. Feb 8, 2022 at 8:17 AM
    #13
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    96761-35035 Engine Coolant Pipe O-Ring
    $4.11

    96761-24019 Engine Coolant Pipe O-Ring $3.83

    part numbers I purchased
     
    Last edited: Feb 8, 2022
    terrward likes this.
  14. Feb 8, 2022 at 8:26 AM
    #14
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    While I was in there I also replaced these coolant crossover seal/gaskets, there were two total in the front, there is also two in the rear (didn’t mess with those)

    [​IMG]
     
    Last edited: Feb 8, 2022
  15. Feb 8, 2022 at 8:51 AM
    #15
    andyman0369

    andyman0369 New Member

    Joined:
    Feb 7, 2022
    Member:
    #74283
    Messages:
    5
    Gender:
    Male
    Nashville
    Thanks a ton Jerry!
    I didn't tear that deeply into it as I was only doing timing belt / front of engine work. I'll def get those done if I need to pull the intake.
    Looks like some sleep and a patient parts tech was what I needed.
     
  16. Feb 27, 2023 at 10:49 PM
    #16
    runna91

    runna91 New Member

    Joined:
    Feb 27, 2023
    Member:
    #92887
    Messages:
    3
    Gender:
    Male
    First Name:
    Justin
    Vehicle:
    2003 Toyota 4runner V8 Limited
    Hey Jerry, might be a long shot but I have the same engine in my 03 4runner. Was wondering what part #s you used for those front bypass pipe gaskets?
     
  17. Feb 27, 2023 at 10:56 PM
    #17
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    @runna91 the ones in the picture below?

     
  18. Feb 27, 2023 at 11:00 PM
    #18
    runna91

    runna91 New Member

    Joined:
    Feb 27, 2023
    Member:
    #92887
    Messages:
    3
    Gender:
    Male
    First Name:
    Justin
    Vehicle:
    2003 Toyota 4runner V8 Limited
    @jerryallday yes! Exact ones! I believe that’s where my coolant leak is currently. I attached a picture where some coolant has pooled up, a lot has pooled up under my intake manifold as well.

    C54F1ADA-FB73-49BA-97A5-61AD78FA781F.jpg
    EFF9B5C0-239C-40BB-B921-8D0E7D0C4E9A.jpg
     
  19. Feb 27, 2023 at 11:28 PM
    #19
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    It looks like it might be the o-right that goes from the thermostat housing and connects to the bypass and it’s just pooling up there. Since it’s wet pretty high. In the photo shown.

    [​IMG]

    Looking thru my emails, trying to find the part number for the bypass seals, Please double check with dealer
    Gasket - Toyota (16341-50020)
     
    Last edited: Feb 27, 2023
    runna91 and shifty` like this.
  20. Feb 28, 2023 at 5:01 AM
    #20
    shifty`

    shifty` He Switched From Rum to Whiskey

    Joined:
    Jun 20, 2020
    Member:
    #48239
    Messages:
    18,554
    ATL
    Vehicle:
    '06 AC Limited V8/4WD
    (see signature for truck info)
    @runna91 it looks like the Toyota Parts system lists a lot of T4R as using his part number, click on 'What This Fits' box here: https://parts.toyota.com/p/63047124/16341-50020.html

    If you need help with the Toyota Parts system to confirm and order the parts, check this thread.

    MAKE SURE YOU DON'T ORDER YOUR PARTS ON scAMAZON -or- fleaBAY!!!


    Actually, here's a copy-paste of the T4R in the compatibility list:

    upload_2023-2-28_8-3-7.jpg
     
    runna91 likes this.
  21. Feb 28, 2023 at 5:30 AM
    #21
    runna91

    runna91 New Member

    Joined:
    Feb 27, 2023
    Member:
    #92887
    Messages:
    3
    Gender:
    Male
    First Name:
    Justin
    Vehicle:
    2003 Toyota 4runner V8 Limited
    @jerryallday thanks again! I will double check the part numbers. Also thanks @shifty` for all the good info! I’ll look into that thread.
     
  22. Feb 28, 2023 at 5:40 AM
    #22
    shifty`

    shifty` He Switched From Rum to Whiskey

    Joined:
    Jun 20, 2020
    Member:
    #48239
    Messages:
    18,554
    ATL
    Vehicle:
    '06 AC Limited V8/4WD
    (see signature for truck info)
    You're welcome. Now hurry up and buy a 1st Gen Tundra, and hang out more :rofl:
     
  23. Sep 13, 2023 at 4:36 PM
    #23
    SunMountain505

    SunMountain505 New Member

    Joined:
    Jun 3, 2023
    Member:
    #98047
    Messages:
    18
    Gender:
    Male
    Hi @jerryallday I believe I found a leak in my coolant crossover seal/gasket on the passenger side. Do you know if I can replace these gaskets without pulling the whole manifold? Should I replace both or just the leaky one? It looks like the same gasket is interchangeable on the left and right side of the engine correct? Does the coolant need to be completely drained first? Thanks a lot !!
     
  24. Sep 13, 2023 at 5:44 PM
    #24
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    I don't think you can access them without lifting the Manifold. I say just replace them both while you are there since you are going to disturb the seal.

    I did it with an engine full of coolant. I just took some out of the top of the radiator, You will make a little mess. Might be a good time to replace the thermostat and seal since you have the coolant out. Preventive maintenance
     
  25. Sep 13, 2023 at 5:48 PM
    #25
    SunMountain505

    SunMountain505 New Member

    Joined:
    Jun 3, 2023
    Member:
    #98047
    Messages:
    18
    Gender:
    Male
    Thanks a lot @jerryallday. So there will be a manifold gasket as well to replace. Any other gaskets? Thanks!
     
  26. Sep 13, 2023 at 5:54 PM
    #26
    shifty`

    shifty` He Switched From Rum to Whiskey

    Joined:
    Jun 20, 2020
    Member:
    #48239
    Messages:
    18,554
    ATL
    Vehicle:
    '06 AC Limited V8/4WD
    (see signature for truck info)
    On the '05-'06 I don't think so. I'm pretty sure it's a rubber molded gasket, not the one from the earlier models.
     
  27. Sep 13, 2023 at 6:02 PM
    #27
    SunMountain505

    SunMountain505 New Member

    Joined:
    Jun 3, 2023
    Member:
    #98047
    Messages:
    18
    Gender:
    Male
    @jerryallday Its a 2004 4.7. So there will or won't be a gasket in the manifold to replace? Thanks for the help.
     
  28. Sep 13, 2023 at 6:04 PM
    #28
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    -Manifold gasket (mine was 2 pc and we sold separately) RED
    -Cross over gaskets - GREEN
    -O ring for crossover - Blue

    -Purple is the rear crossover (not sure if you want to do those at the same time.
    [​IMG]
     
    SunMountain505 likes this.
  29. Sep 13, 2023 at 6:07 PM
    #29
    jerryallday

    jerryallday [OP] New Member

    Joined:
    Jan 4, 2021
    Member:
    #57084
    Messages:
    697
    Gender:
    Male
    First Name:
    Jerry
    Pasadena, Ca
    Vehicle:
    2006 Tundra DC SR5 Grey
    Last edited: Sep 13, 2023
  30. Sep 14, 2023 at 2:21 PM
    #30
    BubbaW

    BubbaW Been Real

    Joined:
    Aug 19, 2019
    Member:
    #34845
    Messages:
    3,278
    First Name:
    Bubba
    Where Eagles Nest
    Vehicle:
    04 DC LTD 4X4 4.7 V8
    T150 Lover

Products Discussed in

To Top