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Cleaning the EGR cooler. Or Not!

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Boffin, Mar 11, 2020.

  1. John48

    John48 New Member

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    Mendel,
    Were you able to remove the EGR Cooler lower nut and stud (“highlighted in yellow” identified in your post dated Oct 25, 2022) without removing any other item/component? If so, could you please explain in detail how you were able to remove the stud and nut? For example; did you use a mirror and flashlight? Did you use a magnetic 12 mm socket and magnetic E8 Torx socket? Did you use 1/4" or 3/8" drive socket set? Any additional information you can provide would be greatly appreciated. I plan on removing the nut and stud this coming week.
    Note: On my 2014 Toyota Prius it’s extremely difficult to run your hand along the side of the EGR Cooler with all of the hoses, high voltage wires, piping, etc.

    Thank You!
     
  2. ASRDogman

    ASRDogman Senior Member

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    You need to use a real 1/4 drive, like snap on. Craftsman are too big.
    A swivel socket, or joint with an extension is the easiest way to get the nut off.
    Then the torx bit to remove the stud.
    Most people do not reinstall them... But it's not really hard with the proper tools.

    You'll have to loosed wire wraps to move them around to be able to reach everything.
    It can be tricky to do, but if you take your time and look at it, you can figure it out.
    And it gets easier each time. Unless you have a long time between each service.
     
  3. John48

    John48 New Member

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    Thank you very much for the information.

    I plan on removing both the nut and stud permanently.

    I also plan on removing the lower EGR Cooler bracket specific to the referenced nut and stud after I remove the Cooler; that way I will not have to deal with it when I install the EGR Cooler next month.
     
    #63 John48, Mar 24, 2024
    Last edited: Mar 24, 2024
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    To remove the lower cooler nut, little or nothing else needs removal. I happened to have a 1/2” drive, Jet brand, ratchet wrench with swivel head. I had a 1/2” to 3/8” adapter on it, then I’m a little fuzzy: mighta just been a long 12 mm socket, or a 1.5” extension and short socket. You need a minor amount of extension, it’s really hard to snake the wrench in (swivel head helps), and to find a space to rotate wrench handle.

    to get the associated stud out, I used a 1/4”, diminutive Jet wrench with E8 Torx socket, “maybe” with short extension. It was very difficult to break loose (dissimilar metals) and it took me at least 15 sweaty minutes. Could only rotate wrench handle one click at a time, and I was afraid of rounding off the stud’s Torx indentations. It resisted virtually all the way out.

    no magnetic gizmos used IIRC; you can get finger tips on everything. Sometimes reaching a left hand around clockwise from left side is easiest to reach it, say when trying catch nut or stud as it becomes free.

    my take: the Toyota engineers did not consider this component would be needing occasional removal, and it’s just dumb luck it’s possible.
     
  5. rjparker

    rjparker Tu Humilde Sirviente

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    Most parts are on the engine when the assembly line installs the engine. There are many jobs where they recommend pulling (actually dropping) the engine. One such job is the timing chain or gasket; originally the brake booster; any short block work, transaxle etc. A good mechanic on a lift can drop it and the subframe in a couple of hours or less.
     
    Mendel Leisk likes this.
  6. John48

    John48 New Member

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    Mendel; Thank you very much for the detailed response on removing the lower cooler nut and stud. I tried to remove the nut yesterday (25 Mar 24); but after I maneuvered the 1/4" drive socket 12 mm, extension (short and long) and racket wrench through the maze of hoses, wires, etc. I was concerned that the socket and/or extensions were going to separate and fall to no man's land (figure of speech). If they separate and fall to no man's land (figure of speech), I'm not sure if I could retrieve them.
     
    Mendel Leisk likes this.
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Well sooner or later you'll need to remove at least the nut. Maybe stuff a towel in the drop zone. I found it not too hard to catch; you can get finger tips on it IIRC. Another trick: jam a small amount of tissue paper into the socket, just enough that the nut's kinda jammed into the socket. And hey, if it drops, no loss...

    Another trick to consider: break the nut loose, then switch to E8 and start backing out the stud, with the nut on the end.

    Note too:, when the nut comes completely off the thread studs, it's still in the zone at the end of stud with the torx "teeth", won't drop if you're careful.
     

    Attached Files:

    #67 Mendel Leisk, Mar 26, 2024
    Last edited: Mar 26, 2024