EGR Cooler Bottom Torx Stud Removal

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by PriusII&C, Apr 13, 2021.

  1. PriusII&C

    PriusII&C Member

    Joined:
    Oct 15, 2013
    175
    66
    0
    Location:
    San Jose, California
    Vehicle:
    2012 Prius
    Model:
    II
    I tried to remove my 2012 Prius EGR cooler today, but got stuck. After removing the bottom nut (it was actually pretty loose), I have difficulty in removing the torx stud. First the space is so limit that I can only rotate the ratchet around 30 degrees, so most of the time it cannot engage to the next tooth. In addition, the torx stud is very heavy, it makes me to wonder if I am tightening it. I rotate it counter-clock wise.

    Please let me know your experience.
     
  2. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,189
    15,317
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    I just leave the stud there;).

    No need to remove it(y).
     
    Merkey and mikey_t like this.
  3. PriusII&C

    PriusII&C Member

    Joined:
    Oct 15, 2013
    175
    66
    0
    Location:
    San Jose, California
    Vehicle:
    2012 Prius
    Model:
    II
    Then do you need to remove the two torx studs connecting to the exhaust? In that case some people say it will be very difficult to put the cooler back. Is that true?
     
    Raytheeagle likes this.
  4. sLick415

    sLick415 Member

    Joined:
    Apr 30, 2012
    214
    54
    0
    Location:
    San Francisco, CA
    Vehicle:
    2012 Prius
    Model:
    Three
    Yep, remove the 2 studs from the exhaust. Do not forget there is a gasket there like I did. It's not held in place by any clips so it'll slip right under once the coolers free from the exhaust. The tricky part when putting the cooler back is getting the gasket and the cooler properly aligned while getting the studs back in. But it's still much easier than trying reach under the cooler.
     
    Raytheeagle likes this.
  5. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,189
    15,317
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    Remove the rear studs;).

    I've done the job about a dozen times and putting the cooler back on isn't near as difficult with the windshield wiper cowling off:).

    Just keep the below cooler bit off and you'll be fine the next round(y).
     
  6. AW82

    AW82 Member

    Joined:
    Mar 22, 2021
    180
    90
    0
    Location:
    Madison, WI
    Vehicle:
    2012 Prius
    Model:
    Two
    Lots of people say to leave the lower nut on the exhaust attachment point off. Is that what you're referring to? Or are you saying remove the lower side stud on the side of the engine block after removing the cooler and then leave the stud out when you put the cooler back in?
     
  7. PriusII&C

    PriusII&C Member

    Joined:
    Oct 15, 2013
    175
    66
    0
    Location:
    San Jose, California
    Vehicle:
    2012 Prius
    Model:
    II
    Following @Raytheeagle and @sLick415 's advice, I removed the two rear studs, and removed the EGR circuit successfully. Thank you.

    Following @AW82 said, could the bottom torx stud be left removed? It looks to me that the assembly is mounted securely enough without it.
     
    #7 PriusII&C, Apr 13, 2021
    Last edited: Apr 13, 2021
    Raytheeagle likes this.
  8. PriusII&C

    PriusII&C Member

    Joined:
    Oct 15, 2013
    175
    66
    0
    Location:
    San Jose, California
    Vehicle:
    2012 Prius
    Model:
    II
    2012 Prius 113200 miles. Still can see light through cooler though. Hardly see any carbon deposit in the small EGR package.

    How important is it to take off the plastic cover of the valve? I tried with an impact screwdriver, but the screws wouldn't budge. It looks like I may damage the screws if trying harder.
     

    Attached Files:

    #8 PriusII&C, Apr 13, 2021
    Last edited: Apr 13, 2021
    Raytheeagle likes this.
  9. sLick415

    sLick415 Member

    Joined:
    Apr 30, 2012
    214
    54
    0
    Location:
    San Francisco, CA
    Vehicle:
    2012 Prius
    Model:
    Three
    You probably could nix the lower stud but you might hear a slight rattle. Maybe put some tape over the lower mounting point of the cooler.

    There should be 4 gaskets:
    - pipe to elbow
    - elbow to valve
    - valve to cooler
    - cooler to exhaust manifold

    You can get by without taking off the cover but it does allow you to push open the plunger so you can make sure to clean any buildup between the plunger and the valve body. I took mine off with a JIS screwdriver (#2 I think). Also a 2012 and I live 2 blocks from the beach.
     
    #9 sLick415, Apr 13, 2021
    Last edited: Apr 13, 2021
  10. Mendel Leisk

    Mendel Leisk Sand Pounder

    Joined:
    Oct 17, 2010
    45,582
    32,540
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I took it out, mainly to be shut of it. It took upwards of 1/2 hour, due (as you noted) to the very limited swivel room with ratchet. Every twist I was stressing that I might round off the head, so went very cautiously. And yeah counterclockwise is the correct direction lol. Dissimilar metals is the likely culprit for the high resistance. It gradually gets easier, towards the end.

    once off, I reunited it with its nut and chucked it in my “spare Prius stuff box”.
     
    Raytheeagle likes this.
  11. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,093
    2,671
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    I took out the bottom EGR cooler nut and stud as well. That's one battle I'd rather not have, EVER again.

    Took me almost an hour to get everything off.

    Also, I hate the Toyota OEM hose clamps. They are almost impossible to get to and clamp properly so they can be wiggled back off the hose mounting area and then put back into position later.

    I replaced all the hose clamps with good quality (hopefully) worm drives to make next time much easier.

    Posted via the PriusChat mobile app.
     
  12. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,093
    2,671
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    Also, does everyone remove that largish coolant hose that goes to the block next to that bottom bracket on the cooler for easier access to the bottom nut/stud?

    Posted via the PriusChat mobile app.
     
  13. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,093
    2,671
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    I also found it very difficult to remove. It seemed to almost be tightening when going counter clockwise. But clockwise was definitely tightening the stud.

    So I persisted going in the counter clockwise, and didn't seem to be making any progress, but kept going, and finally after much turning, it finally came off. The end looked kinda cooked and whitish, almost like it was exposed to the combustion chamber or something.

    Posted via the PriusChat mobile app.
     
    #13 xliderider, Sep 4, 2021
    Last edited: Sep 4, 2021
  14. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    14,683
    10,317
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Once I had the nuts off, and the two end studs (which were easy), I found absolutely no need to disturb the bottom stud; I just slid the cooler right off of it. I can't think of any reason I would work as hard as reported in some of the posts here to do something I had absolutely no need to do. When I was putting the cooler back on, it was handy still having that stud there to hang it on while getting the other holes lined up.

    Remote Access Hose Clamp Pliers for the win!

    There is a reason for the hated clamps. The rubber of the hose does slowly 'flow' under the clamp pressure with time. The spring clamp keeps right up and applies the same pressure years down the road. The worm-drive clamp is eventually loose, and then someone comes around and overtightens it.

    I bought two Gen 2s that had had work done, and the radiator hoses replaced with worm clamps. The first one leaked. The second, I took the worm clamps off right after purchase and put the specified clamps back on.

    I used the remote access pliers in my recent EGR cooler job and I think it all went without a single hose-related cuss word. That's a big improvement over past jobs when I didn't have those.
     
    burrito likes this.
  15. Mendel Leisk

    Mendel Leisk Sand Pounder

    Joined:
    Oct 17, 2010
    45,582
    32,540
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    My reasoning: I’d taken off, and left off permanently, the nut on that stud. So, the stud still there is doing nothing except stopping you from pulling the cooler forward; you have to shift it laterally off the stud first, and to accomplish that you need to ratchet off the two rear studs.

    I won’t know for sure till next time, but I think if I now remove the top/central bolt, the top/front nut and stud, and the two rear nuts (but leave the rear studs on), I’ll be able to pull the cooler straight forward and out.
     
  16. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,093
    2,671
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    I think I'm with Mendel on this one. I don't want to spend more time than necessary lying on top of the engine, reaching down to get at those studs next time.

    The thing I found tricky too is how to insert and hold onto the rear gasket to prevent it from falling down, behind the engine, while removing and reinstalling the EGR cooler and removing/installing the rear two studs? I used a pair of clamping hemostats while removing, and the hemostats to place the gasket, and a hex key temporarily inserted as a holder for the gasket, through one of the two holes while reinstalling.

    Really Toyota, you couldn't put some "ears" bent over the sides of this metal gasket like the one on the back of the EGR tube up front, which by the way, is so much easier to grab onto and hold than at the back of the ever loving engine bay. 20210903_171328.jpeg

    Posted via the PriusChat mobile app.
     
    Mendel Leisk likes this.
  17. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,093
    2,671
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    @ChapmanF, are you sure that the head or business end of those fancy hose clamp pliers can get into and be properly positioned on some of the really tight spots.

    Also, they're pretty pricey for the reliable ones out there. I may have to go see about one on my next shopping trip to Harbor Freight in about three weeks.

    Posted via the PriusChat mobile app.
     
  18. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    14,683
    10,317
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    I can't guarantee there isn't some hose somewhere that would be a struggle, but having just done an EGR cooler job on a 2010 six or so weeks ago and used the remote clamp pliers to do it, I can report success with all the clamps involved in that job.
     
    #18 ChapmanF, Sep 4, 2021
    Last edited: Sep 4, 2021
    xliderider likes this.
  19. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,093
    2,671
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    Thanks, I used an extra long pair of needle nosed pliers with an angled tip. And the handle kept getting in the way of all the hoses and orange HV harnesses, and regular harnesses.

    And those blasted clamps kept slipping out of the pliers, and because one side of the clamp has two sides and is under different tension, tend to rotate away from the position it needs to be in to make another futile attempt at grabbing it again. Lot's of cussing and perspiration here.

    Posted via the PriusChat mobile app.
     
  20. Mendel Leisk

    Mendel Leisk Sand Pounder

    Joined:
    Oct 17, 2010
    45,582
    32,540
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    With the bottom stud removed, my (so far untested) thought is you can leave the rear studs on, and accordingly, you can hang the rear gasket on those studs when installing.
     
Loading...