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

Tundra Heater Line(?) vs 100-LC

Discussion in '1st Gen Tundras (2000-2006)' started by DarkMint, Mar 18, 2025.

  1. Mar 18, 2025 at 4:14 PM
    #1
    DarkMint

    DarkMint [OP] just gettin by

    Joined:
    Apr 12, 2021
    Member:
    #61680
    Messages:
    517
    First Name:
    Ben
    Vehicle:
    2004 Tundra DC SR5 4WD
    Been doing a lot of reading on the 100-series land cruiser, especially on their maintenance item of the "heater tee" at the rear of the engine. Upon inspection of my 2UZFE it appears to have a completely different design. Can someone with knowledge of our iteration of the 2UZ provide some insight on how our trucks differ in design, and what those lines are for? The little black dingdong bolted to the firewall says Denso on it, seems to have some kind of vent holes on the back part.

    Where I was reading about the "heater tee" design as seen on land cruisers: https://forum.ih8mud.com/threads/diy-replacing-heater-hose-pipe-ts-important.610334/


    2004 Tundra DC SR5:

    686B7E28-1985-48B4-9CB3-4872D2E8EAAA.jpg
     
  2. Mar 18, 2025 at 4:22 PM
    #2
    w666

    w666 D. None of the above

    Joined:
    Dec 17, 2019
    Member:
    #40020
    Messages:
    1,755
    Gender:
    Male
    Maryland
    Vehicle:
    04 Access Cab SR5 V8 4WD
    None yet
    Correct...the LC has these two plastic "T" fittings that degrade, begin to leak, and then quickly fail. Hot water is provided continuously to the inside of the cockpit, and the temperature controls regulate how much flows into the heater core. You don't mention which vehicle you're having a problem with. The Tundra has an external valve on the firewall (as per your pic) that lets hot water into the heater core depending on how you have set the internal temperature control
     
    DarkMint[OP] and BubbaW like this.
  3. Mar 18, 2025 at 4:37 PM
    #3
    The Black Mamba

    The Black Mamba He must increase, but I must decrease - John 3:30

    Joined:
    Sep 6, 2023
    Member:
    #103472
    Messages:
    4,155
    First Name:
    Ryan
    DFW
    Vehicle:
    Black 00 SR5 AC 5VZ PreRunner
    Imma keep it stock
    Do remember that the LC100 was designed and manufactured in Japan as well as China. They were originally designed as right hand drive and later adapted to left hand drive for the US market. While the FGT shares some components with the LC100, the are not the same. As for your "heater tree", our FSE calls it a Water Valve. I didn't find any maintenance listed for it other than inspection.


    Screen Shot 2025-03-18 at 6.31.14 PM.png
    Screen Shot 2025-03-18 at 6.35.04 PM.png
    Screen Shot 2025-03-18 at 6.35.41 PM.png
     
    DarkMint[OP], FrenchToasty and BubbaW like this.
  4. Mar 19, 2025 at 6:28 AM
    #4
    BubbaW

    BubbaW Blessed 2 B above Ground

    Joined:
    Aug 19, 2019
    Member:
    #34845
    Messages:
    3,763
    First Name:
    Bubba
    Where Eagles Nest
    Vehicle:
    04 DC LTD 4X4 4.7 V8
    T150 Lover
    The main difference is 1st Gen Tundra uses mechanical water valve to adjust for hot/cold mixture whereas LC100 uses electrical Air Mix Servomotors to adjust the mix of hot and cold.
     

    Attached Files:

  5. Mar 19, 2025 at 10:24 AM
    #5
    DarkMint

    DarkMint [OP] just gettin by

    Joined:
    Apr 12, 2021
    Member:
    #61680
    Messages:
    517
    First Name:
    Ben
    Vehicle:
    2004 Tundra DC SR5 4WD
    thanks guys. Seems like the Tundy design is less prone to failure vs the Hundy design due to mechanical valve and keeping heat out until switched for?
    Will be doing a multi-part maintenance job in a couple months so I want to have all my bases covered while the coolant is out. Will inspect this "water valve" then.

    any of you inspected this Water Valve before or is it generally a leave-it-alone item? I dont hear much talk of it on here
     
  6. Mar 19, 2025 at 11:31 AM
    #6
    The Black Mamba

    The Black Mamba He must increase, but I must decrease - John 3:30

    Joined:
    Sep 6, 2023
    Member:
    #103472
    Messages:
    4,155
    First Name:
    Ryan
    DFW
    Vehicle:
    Black 00 SR5 AC 5VZ PreRunner
    Imma keep it stock
    Do you have a copy of the FSE? If not, get you one
     
  7. Mar 19, 2025 at 12:09 PM
    #7
    DarkMint

    DarkMint [OP] just gettin by

    Joined:
    Apr 12, 2021
    Member:
    #61680
    Messages:
    517
    First Name:
    Ben
    Vehicle:
    2004 Tundra DC SR5 4WD
    Do you mean FSM?
     
  8. Mar 19, 2025 at 12:50 PM
    #8
    The Black Mamba

    The Black Mamba He must increase, but I must decrease - John 3:30

    Joined:
    Sep 6, 2023
    Member:
    #103472
    Messages:
    4,155
    First Name:
    Ryan
    DFW
    Vehicle:
    Black 00 SR5 AC 5VZ PreRunner
    Imma keep it stock
    Yeah, that one
     
    DarkMint[QUOTED][OP] likes this.
  9. Mar 19, 2025 at 3:59 PM
    #9
    w666

    w666 D. None of the above

    Joined:
    Dec 17, 2019
    Member:
    #40020
    Messages:
    1,755
    Gender:
    Male
    Maryland
    Vehicle:
    04 Access Cab SR5 V8 4WD
    None yet
    The Black Mamba likes this.

Products Discussed in

To Top