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Changing engine coolant

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by tochatihu, Apr 12, 2007.

  1. Wilsid

    Wilsid Junior Member

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    I forgot to tell you the 2 hoses were really soft, the heater hoses all seem to
    be in good shape, there are 19 of them, O'reilly's priced them at $300. The 2
    hoses were $32 and I have peice of mind. Thanks for thermostat location,I'll
    look for it.
     
  2. w2co

    w2co Member

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    Thanks all for all this great information as I will soon be changing out the engine water pump (small leak around the pulley near the bearing). Will try draining from the CHS and then filling/bleeding using radiator vent and actuating the CHS etc. Maybe use that funnel if I can order it in time. Great info!
     
  3. Mike500

    Mike500 Senior Member

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    1 person likes this.
  4. w2co

    w2co Member

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    The Uview 550000 looks like a handy device to have around. About a week away from doing the water pump here. I think I'll call tomorrow.
    Thanks for that link Mike.

    On another thought, in case I don't get the above in time, I was going to drain the system mostly by the chs pump drain since it is the lowest thing in the system. How about jacking up the rear end of the car to help drain any trapped coolant out, then jack up the front of the car to fill it. I use ramps to do this, it should minimize trapped air while it is filling up, the coolant will force the air out the radiator. But with the above lifting tool non of this is needed. Ideas???
     
  5. maverick1970

    maverick1970 Junior Member

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  6. 3xJ

    3xJ Junior Member

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    Many thanks for this wonderful thread! Changed yesterday both inverter and engine coolants with no trouble at all. Drained off total about 8.3 liters by opening all described drain valves. Did not face any trouble with filling either of the compartments (remember to open the bleed valves!). The described trick to run the electric pump for engine coolant worked like a charm, did not have to run the engine at all during the filling procedure and was able to put in the same amount that was drained off. Again, manyt thanks for everybody who has been posting to this forum.
     
  7. edthefox5

    edthefox5 Senior Member

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    Not neccessary to jack the car up and down to get the last drop out as the coolant will be pretty good to begin with. Jacking the car up in the front helps with airlock though.
    I had a brand new ulift and was hoping I didn't need to drain the chs as my coolant looked real good anyway. Problem is the adapter that comes with the 55000 kit does not fit the rad fill hole real good and even with the ulift you still have to use Patricks paperclip trick and turn on the chs pump as the ulift will not get that airlock out. THis in addition to crawling all the way under the car and opening the block drain under the exhaust mani and the rad petcock.
    If you just drain out of chs air will get trapped in the chs. You have to turn the chs pump on.
    ICE Coolant replacement is a real pain on this car. Inverter is easy though.
    So plan on doing the chs turn on trick in addition to the ulift. The ulift is a very good tool but not so much on this car. Its hard to handle the ulift with just one person. You'll see what I mean.
    And while your all dirty do the inverter coolant too. Thats way more important.
    And much much easier.

    Then when done watch the rad coolant level closely for the next few days. Listen real close in the cabin for any gurgling.
     
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  8. prius213

    prius213 New Member

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    Thanks to everyone's post here, making this a DIY job. Much appreciated!

    I didn't read anything mentioned about using the bleed valve on the top of the radiator as part of the process. Did anyone use that bleed valve? Or any reasons why this shouldn't be utilized? It appears to be on top of the radiator and opened via a 6MM hex allen bolt.
     
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, you need to open the valve to help get air out of the radiator.
     
  10. prius213

    prius213 New Member

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    Thank you for the help.

    The spec calls for 13 in-lb. of torque for that radiator bleed valve. I was just planning to hand tighten (don't have a torque wrench that goes that low)...anyone know if that is easy to strip out?
     
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hand tightening is fine. Note how much effort is required to open the valve and try to use that same force when closing it.
     
  12. prius213

    prius213 New Member

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    ok great, thanks
     
  13. prius213

    prius213 New Member

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    I had a question pertaining to the CHS pump electrical connector. It is mentioned to disconnect in the procedures explained by others.

    Are you folks referring to the electrical connector on the CHS tank itself or the electrical connector on the actual pump (believe it sits above the CHS tank)? Also, is there any reason in particular this electrical connector needs to be unplugged? Thanks for the help.
     
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Which post are you referring to?

    I suggest the need to remove the coolant heat recovery system relay. The point of removing the relay is to manually bridge the relay socket with a jumper, in order to activate the CHS pump, as part of the process of getting air out of the engine coolant loop.
     
  15. 04prius123

    04prius123 Junior Member

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    Dear All:

    I have an idea that I would like to run by you. I have that special funnel that attaches directly to the radiator cap. I was thinking of filling the funnel all the way up before opening the drain plug. Then open the drain plug slowly. The liquid drained should be refilled fully with the new liquid in the funnel due to pressure head. If one makes sure the liquid in the funnel never runs out ( refill when the level starts going down) there shouldn't be any air introduced to the system. I was thinking of putting in 1 gallon in and if this works I will change another 1 gallon next weekend. Do you see any problem with this approach?

    The only issue is that it is not fully changing the coolant but rather partial change and I can live with that. Thank you
     
  16. xs650

    xs650 Senior Member

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    That is very good advice on any fluid change, including Prii transmissions. Be sure you can open any necessary orifices required to finish the fill job before you drain the original fluid.
     
  17. tommymommy

    tommymommy Member

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    image.jpg image.jpg ]


    Here are a couple of pix I found posted by another DIYer that show the relay & jumping across it. I just used a piece of coated wire with the ends exposed.
     
  18. Wheelin1

    Wheelin1 Junior Member

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    Lisle 24680 Spill-Free Funnel-- THE NEW & IMPROVED version of the 24610 model on eBay for 30 bucks free shipping.
     
  19. SageBrush

    SageBrush Senior Member

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    G2 Prius at 165k miles

    I drained and replaced the engine and inverter coolants today, and figured it was a good time to replace the thermostat and engine water pump as preventive maintenance. I disassembled the top pulley and found it in good condition after 160k miles, as was the belt after 50k miles.

    If I never have to replace a Prius thermostat again, it will be too soon. Those two stinking bolts took me *hours* to remove. I finally got the top one out by reaching down to it; and the bottom one was reached from under the car. My bentley manual says it is an easy replacement, just to add a bit of salt to to my scrapes.

    The inverter coolant change was a joy. First I drained from below and then replugged. I then added fluid to the reservoir until the full mark, and then opened the air escape valve with tools until I could open and close by hand.
    I attached a 3 ft tube bought at Lowes (0.25 inch ID) to the valve and hung the other end in the opening of the reservoir and opened the air valve.
    Then I turned on the pump by tapping on power button twice *without* holding down the brake. This puts the car in Ig-on mode. For the next 10 - 15 minutes or so I happily watched air gurgle out into the tubing, and added fluid to the reservoir when needed. When only fluid came out of the tube for a minute or two I called it a day.

    If only the engine coolant circuit was so easy. Not horrible, just not trivial. A couple of hints:
    • The Lisle funnel is GREAT
    • The air purge valve on the driver's side of the radiator will leak coolant while air is coming out. Best to have a container under the car to catch it.
    • I was unable to figure out how to turn on the HRS pump as Patrick had suggested, so I just cycled the ICE on/off 3-4 times.
    In the future if I just want to refresh the engine coolant, I am going to use the LISLE funnel to exchange a gallon of coolant without introducing any air. I figure every 30k miles or so will be fine.
     
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  20. 08GRAYtour

    08GRAYtour Junior Member

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    I replaced my coolant 2 month ago. Now, I noticed small pink crust under water pump.
    I’ve got a new pump and a belt to replace, but since my coolant is good, don’t want to drain it fully.
    My question for those who know, how much coolant should be approximately drained, so it would be right below the level of the water pump on the motor?