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Replacing Tank Assembly/Reserve Tank

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by WesX, May 23, 2016.

  1. WesX

    WesX Junior Member

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    Recently my car started showing the master warning light along with the temp warning light on the navigation screen. After opening the hood and inspecting, there is a coolant leaking from somewhere. Took it to the dealer and was told there is no leak but a bad/blocked coolant tank assembly. Price to fix is upward of the $2k.

    Question is, if I bought the tank myself for under $1k, could I replace it myself? What would be involved besides replacing coolant? Do I need to get the air out of the lines? Etc.

    Any help would be much appreciated.
     
  2. S Keith

    S Keith Senior Member

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  3. andrewclaus

    andrewclaus Active Member

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    If it's the tank for the coolant heat recovery system (CHRS), you can get a salvaged one here for about $200. You definitely need special tools and instructions to install and bleed the system. There are other threads here covering coolant replacement.

    But I'm concerned why you'd get an overheat warning. Typically when something fails in the CHRS, you only get the check engine light. You say there was a leak--did you see a leak? Have you added coolant? Have you checked the level in the radiator, not just the plastic reservoir?

    Did the dealer give you the diagnostic codes? If you paid for the diagnosis, they should give you those. Post them here if you can get them.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Have you looked at the engine coolant pump bearing to see if dried coolant has deposited on the inside of the pump pulley and on the AC compressor housing? If you see a pinkish deposit, that is the source of the leak.

    As previously stated, it is unusual for a failed coolant heat recovery system canister to cause a leak unless you hit the car in the driver's side front fender. Yes, you could replace the tank yourself, look for a used unit if you can find one for substantial savings.

    I posted on how to replace the radiator coolant and how to purge air out of the engine coolant loop. See my posts #22 and #42 here:
    Changing engine coolant | Page 2 | PriusChat
     
  5. WesX

    WesX Junior Member

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    I had the same problem back at the end of February. Master warning light and overheating icon the nav screen. Popped the hood and there was coolant laying at the bottom of the engine bay. Checked the radiator, overflows tank, etc. and all looked to be ok. A little low but nothing alarming. Took it to the dealer where they did a pressure test of the system and found no leaks at all. Was told that the coolant was about 1/2 gallon low. They filled it and off I went. Was good for a few months.

    Now in May the same lights pop up but this time the check engine light also appears. Took it back in and they the pressure test again along with the dye test to find a leak. Told no leaks in the system. What I was told is there is something in the tank assembly that is blocking the coolant flowing through the system. Which is causing the coolant to come out of the overflow tube and leak all over.

    On a side note, the last few days I'd shut the car off I'd hear the noise of the system pumping coolant into the tank but it didn't sound "normal". Almost like it was dying.
     
  6. WesX

    WesX Junior Member

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    The car was recently in an accident. It was a rear end collision that pushed the car into the car in front of me. There was quite a bit of work that was done on the car. I know some stuff for the radiator and cooling system was replaced. Not sure if the accident had anything to do with the tank assembly or not. Never had the problem before the accident so I'm convinced the shop F'ed it up somehow or the accident had something to do with it.

    Check my post above to see what I was told by the dealer as far as the leak.
     
  7. andrewclaus

    andrewclaus Active Member

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    The accident may have damaged the tank. I wonder if you have any recourse through the insurance claim. You can certainly get a parts list and find out if it was replaced, at least.

    The bad pump sound you heard could be from air in the system. Have you noticed any problem with the cabin heat?

    There's nothing in the CHRS that can physically block the engine coolant system. The CHRS is a small "side arm" off the main loop, sort of like the heater core. Something else is going on. The tank may certainly be damaged, but this explanation of radiator overflow doesn't sound right.

    I suppose there's a remote possibility of a head gasket leak that might not show up in a static pressure test. A very slow loss of coolant could eventually cause your symptoms. Are you in the habit of checking the reservoir level?

    Did you get the code(s) from the check engine light?
     
  8. dolj

    dolj Senior Member

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    I think you are talk at cross purposes.

    I'm fairly certain that the OP is saying the blockage is in the coolant reservoir area, not the CHRS.
     
  9. WesX

    WesX Junior Member

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    The insurance company was called and they told the dealer that it wasn't damaged and there's no way it was caused from the accident so they won't replace it. Never had a problem before the accident so it's hard to believe it didn't. Do the tanks normally go bad at some point or do they normally last the life of the car?

    There is no heat inside the car at all. It was the same problem I had back in February. Master warning light, high temp light, and no heat inside the cabin. They filled the coolant and it fixed itself until now.

    I'm just going by what the tech specialist at the dealer is telling me. They checked a bunch of stuff and narrowed it down to the coolant heat storage tank assembly. The part costs $1100. Adding labor, it's close to $2k to fix.

    I did not get the code from the check engine light. I completely forgot to ask.
     
  10. WesX

    WesX Junior Member

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    I'm pretty sure it's the CHRS. They're telling me the part costs $1,100.
     
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    All you have to do is to jack up the front left corner, take off the tire and remove the front part of the fender liner. Then you can see the CHRS canister.

    If you see coolant seepage then you will have found your leak. If you see a big dent in the tank then you will know it was damaged in the accident.
     
  12. dolj

    dolj Senior Member

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    Thanks for clarifying.
     
  13. WesX

    WesX Junior Member

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    Unfortunately, the car is at the dealer so I can't check on my own. The one thing I'm trying to find out is the life expectancy of the CHRS. Is this a part that eventually has to be replaced or does it last the life of the car?
     
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Life of the car, unless subjected to accident damage.
     
  15. andrewclaus

    andrewclaus Active Member

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    From other threads I've seen on this forum, it sounds like the temp sensor at the tank may fail, not the tank itself, which I think requires a new tank anyway. There are diagnostic codes for that sensor, which is one reason knowing the codes would help.

    If refilling and bleeding the system gets things back to normal, no check engine light and good heat and quiet CHRS pump, I'd take the car and do more diagnostics on it. Inspect the tank, monitor the coolant level carefully over time, maybe get an engine leak-down or compression test done if you can't find a gross leak.
     
  16. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, that is true. I am surprised that it is not possible to separately replace the temp sensor. A new CHRS canister costs $807 here:
    RADIATOR & COMPONENTS for 2009 Toyota Prius
     
  17. WesX

    WesX Junior Member

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    I got the check engine codes today: P0117 , P1150 , P1151
     
  18. WesX

    WesX Junior Member

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    The tank is not physically damaged so the insurance will not replace it because they are saying it's not directly related to the accident. Everyone I talked with said that these tanks never good bad unless in an accident.
     
  19. andrewclaus

    andrewclaus Active Member

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    The first code is the engine temp sensor, the second two are the CHRS tank. The first may have been from the loss of coolant and may reset when coolant is restored. It sounds like you need to replace the tank, and yes you can do it yourself. You need special methods and tools to bleed the system, both covered in other threads here. If you're going to do the work, look into getting a MiniVCI--it makes the bleeding process a snap, and you can monitor the sensor values to help in troubleshooting. Only $25 and an old XP or Win7 laptop. I used a Bentley manual for bleeding instructions (and it has a list of DTCs), but with the internet you don't really need that and its value is limited.

    I still think (guess) you have some other cooling system problem that led to the original overheating episode, and that will require some long-term monitoring and diagnoses.

    If you do coolant work, you may also want to replace the three-way control valve near the CHRS system. It's about $80 and is a common failure point, but also not critical to the car. And it may be time to replace the inverter/transaxle coolant, too.
     
  20. WesX

    WesX Junior Member

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    So for an update...

    Toyota replaced the CHRS tank, just because I don't have the garage, time, or tools at my disposal right now.

    Picked it up after the tank replacement. All seemed to be fine. No lights, no warnings, nothing. Drove 15 minutes down the road, master warning light and overheating light pops on again. Get home, pop the hood and there is coolant laying at the bottom of the engine bay. Call Toyota, take it back in, wait a few days, and they tell me the air wasn't fully bled out of the system. Pick it up, no problems all the way home.

    About 10 or so days go by and all the lights return. Master warning light, overheating light, check engine light, etc. Take it back to Toyota and they tell me that the Coolant Control Valve is bad. It's getting stuck and it's not properly passing coolant through the system. The tech said when he would bang on it the lights would go away. They tell me it caused the tank to go bad. They fix it and off I go. All seems to be fine.

    4 days later, as I'm driving to work, the master warning and overheating light come on for about 10 seconds and go off. Does it again and goes off. Get to work, pop the hood, coolant at the bottom of the engine bay. Drive it home that night, no issues. Next day, on the way to work, same thing. Call Toyota and take it back in. A day or two goes by and they call and tell me they can't get the lights to come on or get it to overheat but can tell it did because of the coolant. They've had it now for almost 8 days and have no idea what's wrong with it.

    Any ideas??