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Transmission fluid leak from radiator, (driver side at bottom)

Discussion in '1st Gen Tundras (2000-2006)' started by Edog, Sep 13, 2025 at 12:41 PM.

  1. Sep 13, 2025 at 12:41 PM
    #1
    Edog

    Edog [OP] New Member

    Joined:
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    First Name:
    eric
    Vehicle:
    2003 Tundra SR5
    I have a constant drip of transmission fluid coming from the lower driver side of radiator that I had replaced in August. The ATF fluid was low so I replaced the the fluid. I cannot determine the exact location of the leak, but when I feel around the lower side of the radiator, I can feel a circle where the fluid is accumulated then leaks onto the skid pan/ underside protector.

    My tundra is a 2003 SR5 with a 4.7 liter, 2 WD.

    thank you for any insight.
     
  2. Sep 13, 2025 at 1:22 PM
    #2
    blackdemon_tt

    blackdemon_tt Battery Slayer

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    TRD Sway Bar, Roll covers USA bed cover
    Maybe try and retighten the feed line to both. I'd start there. If it persists then call the place you got it from and start a warranty claim.
     
  3. Sep 13, 2025 at 2:26 PM
    #3
    ATBAV8

    ATBAV8 Mr. Bentley-He builds fast trucks.~Ettore Bugatti

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    Tempe, AZ
    Vehicle:
    2003 V8 SR5, Access Cab, 4x4, White
    Bilstein 5100s with OME 2884 springs, Firestone RideRite airbags.
    Was it replaced with a Denso radiator?
     
    bing5 and G_unit3000 like this.
  4. Sep 14, 2025 at 2:16 PM
    #4
    bing5

    bing5 Long member

    Joined:
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    New Mexico
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    2004 Double Cab. 270k+
    Like she came out of the factory.
    Not likely that it's related, but I had a power steering cooler leak in about this area, though it's more towards the passenger side. One of the small hoses leading into and out of the cooler had grown brittle and sprung a leak. Dripped right into the skid plate.

    I discovered it when I replaced my radiator....with a Denso :)
     

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