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Little valve beside the valve lift of thermostat

Discussion in 'Gen 3 Prius Main Forum' started by Hsieh2017, Jul 16, 2024.

  1. Hsieh2017

    Hsieh2017 Junior Member

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    2014 Prius
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    Three
    While I teared apart a thermostat of P3, I discovered there is a little valve without any spring loaded beside the valve lift of the thermostat. It makes the thermostat is not fully closed when the water temperature is cold in my testing. Maybe it is some kind of one way valve depending on the coolant pressure? Anybody know what is the purpose of the small valve?
     

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    Tombukt2 likes this.
  2. ChapmanF

    ChapmanF Senior Member

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  3. Tombukt2

    Tombukt2 Senior Member

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    See if they make one of those Robert Shaw balanced stats for your car and that's a pointed shape dome over the top of it looks a lot different than the standard thing you have showing here.