Refill ICE coolant loop through drain valve under thermos?

Discussion in 'Gen 2 Prius Technical Discussion' started by pasadena_commut, Jan 18, 2025 at 1:37 PM.

  1. pasadena_commut

    pasadena_commut Senior Member

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    Typically one drains the Prius ICE coolant loop through the drain valve under the thermos, with the car tilted with the passenger side raised. Then it is filled at the radiator cap. I was wondering the other day what would happen if it was refilled through the drain valve, essentially reversing the drain procedure. This would mean putting a clean tube onto that outlet, attaching a hose clamp (so that the tube doesn't fall off) and then pouring it into a funnel at the other end of the tube from a level higher than the radiator cap.

    Anybody ever tried it? I'm wondering if filling from the bottom might result in fewer problems with stuck air bubbles. Or maybe it would be worse and it couldn't get past the thermos?
     
    #1 pasadena_commut, Jan 18, 2025 at 1:37 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    Why couldn't I bus put the rated amount of cooling in a big container put an air hose to that clamp up like you suggested and fix myself to the container that I have the coolant in and push it in with air not push through it with the air just push it out of the vessel gently up through the drain port you're talking about and then when it's empty then it comes out the cap or something close off that fitting and remove my clamp but if you're going to do all that isn't it cheap to buy that little device that lets you dump the whole amount of cooling in the radiator like all at once especially if you're going to be doing this any kind of regularly.
     
    #2 Tombukt2, Jan 18, 2025 at 2:04 PM
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