Is this a transaxle breather plug? (see photo)

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by wheezyglider, Apr 8, 2019.

  1. wheezyglider

    wheezyglider Member

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    What is this part? Doing an EGR circuit clean on our 2010, I noticed that the part circled in this photo was covered with soot even though nothing around it was sooty. I wiped it some before taking the picture. (That's the EGR pipe removed and EGR cooler still in place with hoses disconnected nearby.) prius_maybe_breather_valve.png
    I think it might be the transaxle breather plug shown as 30900N in this parts diagram in which case it is Part Number: 9093003201 and goes for $3.79. (Probably a "special order" :rolleyes: at my local dealerships.) Is it normal for these things to get sooty? Do they need maintenance?
     
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  2. mjoo

    mjoo Senior Member

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    You're probably right. There's only one of those and it looks like you found it.

    Soot doesn't normally billow out of the transmission. You could have a major transmission problem. Or you could just be driving in a sooty environment or have an exhaust leak.

    Pixel XL ?
     
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  3. ASRDogman

    ASRDogman Senior Member

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    It's probably soot from the EGR system when you removed it.
    I think it is a breather for the transmission. If it's not vented, the heat will build up pressure and possibly blow
    out of the seals. Which would not be good.
     
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  4. Raytheeagle

    Raytheeagle Senior Member

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    All looks like road grime to me;).

    Now how does your cooler look inside:whistle:?

    Good luck and keep us posted (y).
     
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  5. wheezyglider

    wheezyglider Member

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    Hey thanks for the quick input guys. I'm just gonna wipe the breather plug clean for now and not worry about it too much! I'll be changing the tranny fluid soon, hopefully it'll be obvious if things are getting ugly in there.

    The EGR cooler definitely needed cleaning which I wouldn't have considered without PriusChat :notworthy: and the Nuts About Bolts videos -- many thanks (y) to everyone contributing! Cooler barely passed a pinpoint of light end-to-end, and flow under the tap was severely constricted compared to after cleaning. (Cleaning the EGR cooler -- if your OCD kicks in you'll be at that for hours.)
    IMG_7062.JPG IMG_7076.JPG

    I also decided to just flat replace the intake manifold given the TSB and multiple revisions since 2010. The new one looks the same outside except for this basket at the throttle:
    IMG_7022.JPG

    The new IM "assembly" doesn't include the two stud bolts for the throttle body. (Does include the 3 gaskets tho, nice.) Removing studs from the old unit I twisted the torx head off of one, and it's gonna be a few days before I have a replacement, along with a PCV hose.

    So this is all moving at a leisurely pace... If it all comes out well I get to do it for the 2012 (PiP) which has even more miles.:D
     
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  6. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    That basket is interesting; wonder what it's for.
     
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  7. mjoo

    mjoo Senior Member

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    It's good for keeping the robin eggs out of the engine this time of year.
     
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  8. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    #8 Mendel Leisk, Apr 9, 2019
    Last edited: Apr 9, 2019
  9. wheezyglider

    wheezyglider Member

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    Yes, but it gets fun: I had looked at a similar TSB here on PC that specified part 17120-37091 as the latest replacement, so I ordered that. And the box it came in says 17120-37091. But the actual manifold has 17120-37054 printed on it. So warehouse change up? Or is the "manifold assembly" 17120-37091 actually made up of manifold 17120-37054 plus this arctic weather tweak?

    At any rate, toyota.com parts catalog does show the 17120-37054 manifold as being the current thing for my VIN. (And BTW the one I replaced was 17120-37050.)

    IMG_7021.JPG
     
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  10. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    Very interesting, thanks. So you think that grid is a heater eh?

    By-the-bye:

    I use a full feature text editor*, and keep a catch-all file, basically a text format "scrap book" of any-and-all, and gems like you posted go in there, like this:

    ====
    Tuesday, April 9, 2019

    Priuschat info regarding latest 3rd gen intake manifold:

    Location:

    Is this a transaxle breather plug? (see photo) | PriusChat

    Yes, but it gets fun: I had looked at a similar TSB here on PC that specified part 17120-37091 as the latest replacement, so I ordered that. And the box it came in says 17120-37091. But the actual manifold has 17120-37054 printed on it. So warehouse change up? Or is the "manifold assembly" 17120-37091 actually made up of manifold 17120-37054 plus this arctic weather tweak?

    At any rate, toyota.com parts catalog does show the 17120-37054 manifold as being the current thing for my VIN. (And BTW the one I replaced was 17120-37050.)
    ===

    * Info on the editor:

    TextPad - the text editor for Windows
     
    #10 Mendel Leisk, Apr 9, 2019
    Last edited: Apr 9, 2019
  11. wheezyglider

    wheezyglider Member

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    Don't know if it's a heater, but I do suspect the grid is only for the cold weather issue mentioned in T-SB-0103-12 [ https://attachments.priuschat.com/attachment-files/2015/10/96232_T-SB-0103-12.pdf ]. We don't seem to be finding that grid in normal use so far. (Anybody with a 17120-37054 want to check?)

    But clearly I should have been working off the bulletin you referenced above (T-SB-0116-15) because cold weather isn't my issue.

    What's interesting about T-SB-0116-15 is that it prescribes 17120-37054 to replace all manifolds up to and including 17120-37054 itself, to deal with misfires while running. IOW: clean the manifold (by replacing it). Which makes sense in a service center context. Even Toyota doesn't trust the service centers to clean a part properly? :ROFLMAO:

    Honored to make the cut! I use notepad++ for code, but wordpad for my EGR project notes so I can embed images:
    egr log snippet.PNG
    I gathered all the EGR wisdom from PC threads and videos into a big rambling log, but then I distilled that and the NAB videos into step-by-step lists that I can check off to idiot-proof the wrenching. I'd like to find a way to share the written steps here in this forum for other people doing this. They look like this: egr reassembly snippet.PNG

    Pardon the snipping, but I thought you guys might get a kick out of this! :p
     
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  12. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    Steps 29 through 36 above, I suspect Toyota is trying to avoid tensions building up as the cooler, valve and pipe are connected to each other and to the engine, exhaust manifold and intake manifold. Still @NutzAboutBolts just:

    1. Bolts cooler and valve together.
    2. Bolts above assembly to exhaust manifold and engine.
    3. Bolts pipe to valve and intake manifold.

    Both during removal and reassembly, it seemed to me the upper and frontmost stud on the valve was fighting, difficult to remove and install. This could be consequence of not following the Toyota procedure? @NutzAboutBolts noted the same "fighting", in his video.

    I'd suspect they're assembling them at the factory per steps 1 through 3 above, and maybe that's why? Bottom line, I just could not fathom all the temporary tightening and loosening in steps 29 through 36, and doing steps 1 through 3, you manage to muddle through.

    Then there's @Ragingfit's install: 3rd gen EGR on 4th gen engine. It free spans, from the exhaust connection to the intake manifold.

    Yeah take a look at TextPad. It's free to download and try, and as far as I know if you haven't shelled out the 20 pounds or whatever it is these days, there's just a 4~5 second display of the TextPad logo at start up. Things that come to mind that it can do, and I'm just scratching the surface:

    1. Wrap text that has hard returns at line ends.
    2. Put hard returns at the ends of lines of text that's currently wrapped.
    3. Change case, either all upper, all lower, first letter up and rest lower, or first lower lower and rest upper. Don't think the latter would ever be useful.
    4. Insert system date by invoking a hotkey.
    5. Same thing for time.
    6. Sort text lines, alpha/numerically.
    7. Use "regular expressions", ie page breaks, carriage returns and so on.
    8. Search/replace
     
    #12 Mendel Leisk, Apr 9, 2019
    Last edited: Apr 9, 2019
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  13. wheezyglider

    wheezyglider Member

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    Yeah the Toyota repair manual version makes a big deal out of fitting everything and I agree it's probably overkill. Given my track record I'll take extra steps if they reduce the risk of a major hassle (stripped threads). But as a not-frequent mechanic it's also hard for me to measure actual vs. imagined risk.

    So I noticed the engine-side threads on that front stud look different than the stud bolt threads for the exhaust connection. I thought maybe they used anti-seize, but Toyota repair manual doesn't mention it. Side-by-side photo: IMG_7078.JPG
    I'm going to put the cooler back in today but I'm still waiting on those other parts...
     
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  14. Kasra

    Kasra Junior Member

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    I don't think that the soot is from exhaust or anything. The breather plug's purpose is to balance the pressure insire the transaxle. This can be done by realeasing the pressure in both directions. Wear a mask for a day and go on the street; by end of the day, the white mask has captured enough particles that it has shades of black. Now dod the same for the age of the car, and tou will see how dark it looks after years. The plug is in an environment that sees q lot of things past the radiator lol. I wouldn't be worried about it since the pressure gradually changes inside the transaxle, so air will get in an out no problem. I took a picture of my 2015 with 72K miles on it. But if you want to spend the money, go for it. I bet it will look the same within a year :) Please send us an update with a picture after the installation.

    BTW, if anyone wants to service this, its EZ to access it from the top. 20190418_104426.jpeg 20190418_104414.jpeg 20190418_104352.jpeg

    Posted via the PriusChat mobile app.
     
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