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Coolant replacement - do i need to level the car?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by imanony, Dec 19, 2022.

  1. imanony

    imanony New Member

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    I'm changing both engine coolant and inverter coolant tomorrow. I already have my 2012 Prius jacked up in front because of the oil change I did yesterday. Question is do I need to level the car to replace the coolant? I remember hearing about it in one of the videos I was watching. So, I'm wondering if I could replace the coolant while it is up on the front side or do I need to bring up the back as well to level it. Thank you!
     
  2. Tombukt2

    Tombukt2 Senior Member

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    You can fill the coolant regardless remember electric pumps are pumping this fluid around and they can be turned on pretty easily with some computer software that works your car. So there is that the inverter system comes on anytime you push the start button to start to ready the car so that will bleed itself almost immediately fill the jug up watch it drop fill it up watch it drop never take it over the full mark watch it drop some more about the time you think it's not going to drop anymore get in the car push the start button hear that pump start makes a noise watch the level in the jug drop a little more now top it off your pump is pumping keeping the level full running the coolant through the whole system and back to the jug staying full you are what. B l e d. The regular radiator system is very similar but usually people just wind up squeezing fat hoses and milking the coolant through the system because they don't want to bring the laptop out plug into the proper plug and turn on the electric water pump with the software like me I'm too lazy to walk into the shop and unplug the portable computer bring it to the car plug it all up just to run a pump I can just squeeze a hose and get it pretty close the first go around You get used to doing this if you do it a few times.
     
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  3. Siward

    Siward Active Member

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    Well, I did both my inverter and engine coolant last month. I drained the coolant while the car was jacked up, but I filled/bled the coolant while the car was lowered back on to the ground.

    I have been driving around for a month now and I didn't get any temperature codes.
     
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  4. Mendel Leisk

    Mendel Leisk Senior Member

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    Doesn’t matter.

    Front doesn’t even need to be raised, though it’s almost mandatory to raise it a little, to reach an arm through engine underpanel opening, and get a grip on the the radiator drain tap. You may need to reach down from above to break it loose; it can be stubborn. Push some tubing on it if really picky. I did but not sure it’s necessary, not hard at all to catch with a basin of some sort. I used an old laundry detergent pail. Put liter increments on the wall to get some idea how much drained.

    Notes on changing the engine coolant on a gen 3 | PriusChat

    ^ This thread has some info. One of my posts has repair manual excerpts. Do read them: the refill procedure varies from @NutzAboutBolts video some. Basically you fill to B line on reservoir, reinstall cap, run in Maintenance Mode.

    My suspicion: you could skip the MM protracted idle, just drive the car as usual, and everything will shake out.

    Do not bother with the block drain (indicated in repair manual); it’s a total waste, yields 2-3 tablespoons.
     
    #4 Mendel Leisk, Dec 20, 2022
    Last edited: Dec 20, 2022
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  5. imanony

    imanony New Member

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    Thanks everyone. I did all these today and feel happy with the results.
    - Engine coolant flush
    - Inverter coolant flush
    - EGR pipe cleaning
    - Spark plugs replacements

    Did the coolant flush while the car was raised (left it on the jacks after the oil change 2 days ago). While coolant was flushing out, removed everything required to get to the EGR pipe and cleaned it up. Put it all back together and lowered the car and filled up the coolant tanks. Bled out all the air and let it cool for 30 min and before removing everything to get to the spark plugs.
    Dropped one 10mm screw inside and landed on the plastic covering. Couldnt get it out so just left it there. Will see if shakes out itself while driving. :)
     
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  6. Grit

    Grit Senior Member

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    Nice work. How many gallons of new coolant needed to refill both coolant resivior?
     
  7. imanony

    imanony New Member

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    I had bought 3 gallons but used only about 1.75 gallons.
     
    #7 imanony, Dec 20, 2022
    Last edited: Dec 21, 2022
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    What’s the miles on it? How did the EGR pipe look?

    Cleaning just the pipe gives you “some” idea as to the rest of the EGR components condition. There’s the EGR valve/cooler assembly, and EGR passages in intake manifold.

    Consider oil catch can too, to reduce the swill introduced to intake manifold (and likely combustion chamber) by PCV system.

    First couple of links in my signature.
     
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  9. ASRDogman

    ASRDogman Senior Member

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    You didn't get all the older coolant out. You should have also jacked up the rear,
    or lower the front so the car was level. You did get most of it out, so you'll be fine.
    Just remember for next time.
    Cleaning ONLY the egr pipe was a waste of time. It's the cooler and intake passages that
    need the cleaning. Those are what get clogged.
    It's like changing half of the oil and not changing the filter.

     
  10. ColoradoBoo

    ColoradoBoo Senior Member

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    Good job, Imanony! When is the last time she had her throttle body and MAF sensor cleaned? I do mine every 25,000 miles...very easy procedure. I also replace the PCV valve and radiator caps, with OEM from the dealer, every 10 years in our vehicles. (And PCV hose, if it's rubber.)
     
  11. imanony

    imanony New Member

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    It has about 94K miles plus some change. It was too much for one day :), but I do have the valve/cooler assembly cleanup in mind. Will take it up in summer next year.
     
  12. imanony

    imanony New Member

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    I wanted to clean the entire assembly but not for today. Planning on doing it next year in summer.
     
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  13. imanony

    imanony New Member

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    Good point. I dont know when throttle body/MAF sensor was cleaned. I guess that would be my next project. Can you share some details or videos on that?
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Oh for sure. You can also take on the EGR valve/cooler one time, then another week do the intake manifold.

    Beforehand prep a few things too: the lower cooler nut can be removed any time, and just left off. You can also remove the stud there, needs an E8 Torx socket. It’ll be slow going, fights all the way out, and very difficult to use ratchet wrench there.

    With that combo gone, you won’t need to remove rear cooler studs.

    you can also trial remove the nut and stud at the valve, put a little anti seize on and reinstall (torque values in first link in my signature).

    ditto for the bolt at top of cooler.
     
    #14 Mendel Leisk, Dec 21, 2022
    Last edited: Dec 21, 2022
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  15. ColoradoBoo

    ColoradoBoo Senior Member

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    Sure, you'll just need a can of Throttle Body Cleaner and a can of MAF Sensor Cleaner. Unclip then use a small phillips head screwdriver to remove the two screws holding the MAF Sensor in. There's a small wire inside there that you just spray well with the MAF Cleaner. Let dry a few minutes, and spray again. (You don't want to touch the wire, it's very sensitive.) Let dry and replace. Then remove the air intake assembly to expose the Throttle Body. There's a butterfly flap in there that can be slowly moved open and closed...be gentle! Spray the TB Cleaner on a clean rag (don't use paper towels) and wipe out the black gunk all around the butterfly flap. Then push it open and clean the black gunk from both the edges of the flap and a few inches inside of the TB. If it's very dirty, it may take some work and a few towels but you'll know when it's clean. That's it! I've been told if it's very gunky the car will take a few minutes to re-learn the electronic settings but I've only seen this when I did this cleaning to my sons old Suzuki...the Toyotas didn't seem to be affected.
    You can remove the throttle body if it's just filthy but then you'll need to replace a black gasket behind it. Only spray the TB with the cleaner if it's removed, else just use the shop rag which does a great job, you don't want to spray that stuff into the engine.
    The Car Care Nut's YouTube channel has a tutorial on how to do this, I believe.
     
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  16. Mendel Leisk

    Mendel Leisk Senior Member

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    If you want to go further with the throttle body, remove the hold-down bolts and nuts, unclip electrical connection, but leave coolant lines attached, lift it off for cleaning. For reinstalling, torque spec for the bolts/nuts are in the intake manifold Repair Manual excerpt, in first link in my signature.

    I've found it the clamp on the rubber pipe connecting to top of throttle body is a real pain to lock in the loose position. It can be done, but it's finicky. It might even be simpler to just clamp it open with vice grips, faster.

    Screen-grab from aforementioned excerpt, save the trip:

    upload_2022-12-22_9-9-49.png

    Note, 7 foot pounds is pretty light; you'd want to use a 3/8" or 1/4" drive torque wrench. A 1/2" drive likely wouldn't even go that low, and settings near a torque wrenches extremes tend to be inaccurate. If using a 1/4" drive it's likely calibrated in inch/pounds: 7 foot/pounds translates to 84 inch/pounds (7x12). Whatever you do, make sure you understand the diff; you don't want to torque to 84 foot/pounds, lol.
     
    #16 Mendel Leisk, Dec 22, 2022
    Last edited: Dec 22, 2022
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  17. ColoradoBoo

    ColoradoBoo Senior Member

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    Why clean the throttle body and how to do it on Toyota engines?
     
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  18. ColoradoBoo

    ColoradoBoo Senior Member

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    Here's a MAF Sensor removal and cleaning....I learn a lot from this Toyota mechanic's videos

     
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