HVAC heater hoses location and part numbers.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by mypriuscious, Dec 20, 2024 at 9:20 PM.

  1. mypriuscious

    mypriuscious Member

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    In my 2010 Prius I have a coolant leak on the back side of the engine passenger side.
    I searched heater hose in the ‘titles’ and only 6 posts came up. I couldn’t find much of anything on Google either.

    My second problem is that I don’t have heat on passenger side. Don’t know common causes of this or if they are related.

    Any guidance would be greatly appreciated.
     
  2. rjparker

    rjparker Tu Humilde Sirviente

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    There are several coolant hoses on the driver's side with a couple going down to the exhaust heat recirculation system behind the catalytic converters.

    If you just have coolant on the back passenger side it may be the coolant reservoir releasing pressure. Usually the engine is overheating and the coolant releases from under the reservoir cap.

    IMG_6987.jpeg

    Often the engine water pump may be failing or perhaps a head gasket failure.

    There is also a big radiator hose and a small coolant hose on the front passenger side of the engine along with the reservoir on the passenger fender.

    If it is losing coolant in any way, air can keep the heater from working. There are also air mixing servos inside the blower / ac / heater assembly inside the dash. Sometimes one of the servo doors fails and blocks off the heater core. Not likely in this case.

    If gasket sealer was used the heater core could be blocked. This in itself would not cause coolant release but could reduce heater output.

    Overall, find and fix the coolant leak or overheating release. Then fill with coolant and check the cabin heat.

    IMG_6983.jpeg IMG_6984.jpeg IMG_6985.jpeg IMG_6986.jpeg
     
    #2 rjparker, Dec 20, 2024 at 10:17 PM
    Last edited: Dec 20, 2024 at 10:41 PM
    mypriuscious and Brian1954 like this.
  3. Brian1954

    Brian1954 Senior Member

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    How many miles on the car?
     
  4. mypriuscious

    mypriuscious Member

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    Something like 680k
     
  5. Brian1954

    Brian1954 Senior Member

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    Is that a typo? I have never seen someone with that many miles on a Gen 3.
     
  6. mypriuscious

    mypriuscious Member

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    No.
     
  7. mypriuscious

    mypriuscious Member

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    Thanks for the info on the radiator hoses.

    essentially I only have hot air coming out of the driver side D B. Warm air out of the defrost and cold out of the rest.