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'62 Cj5 Exhaust Manifold Broken Studs And Coolant Leak

Discussion in 'Early CJ5 and CJ6 Tech' started by _fletch_, Jul 8, 2019.

  1. Jul 8, 2019
    _fletch_

    _fletch_ New Member

    Kentucky
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    Hello, this is my first post. New to the forum obviously, and think I have a unique issue, but if it's been discussed before, please let me know. My son bought a 1962 CJ5 recently, with the 134 F-head, and we're going through it, fixing things we knew about, and finding a lot of things we didn't know about. I'm an industrial electrician by trade, and although I've done some of my own auto repairs over the years, I am no auto mechanic! Been figuring out a lot by doing, and it's been a great learning experience for my 19-year-old, but we ran into something today that I'm not sure what would be the best way to handle.

    Three of the exhaust manifold bolts were broken off in the block, so I tried to get them out, but finally had to end up center punching them and drilling them out a little at a time until I could finally get the old bolt threads peeled out, and then chased the threads, which are 3/8-16. They are good to go now with one exception. One of them goes all the way through into the block, into what I believe is just the coolant cavity around the cylinders. One of the other exhaust manifold bolts that I didn't have to drill out, is also all the way through into the block. The others bottom out before that point. So I'm wondering if that is the coolant cavity, am I going to have coolant leak issues now? Was planning on putting some type of thread locker on them anyway, probably red RTV, since it's a high temp area... just hope I never have to get them back out.

    Also, another issue which is down on the valve cover, the bolt on the left that goes through the ventilator... when I removed this bolt to remove the valve cover, coolant is leaking out of this threaded hole as well (just residual coolant, as we've removed the radiator at this point). I'm also feeling like this hole should not have been all the way through either. Someone had tried to glob a bunch of blue RTV in that threaded hole, but his engine oil is milky white so obviously coolant is getting in. We've got the head pulled, and although we're going to replace the head gasket now, I don't believe it was allowing the coolant to enter.

    Sorry for the long winded post... but is this making any sense? I can post pics tomorrow if needed.
    Just for the record, this thing ran fine when we drove it home, of course it was louder than normal since the exhaust manifold was hanging off of it, and the death wobble is horrendous (which we're in the process of addressing).

    I'm considering injecting a small amount of JB Weld into these open holes to close them off from the block, then re-drilling and tapping if needs be... unless ya'll feel like the issue can be resolved simply with some kind of thread sealant.

    Any help would be greatly appreciated. Thanks.
     
  2. Jul 8, 2019
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member

    Tantallon, Nova...
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    Welcome. :)

    The exhaust studs on the ends are indeed "wet", the center ones are not.

    For the valve cover, are you talking about the top cover or the one on the side of the block? I'm having trouble visualizing what you're talking about- can you take a pic?
     
  3. Jul 8, 2019
    Greevesman

    Greevesman Member 2020 Sponsor

    Napa, Ca
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    Loctite makes a thread sealant. Not sure about temperature issues.
     
  4. Jul 8, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Permatex #2 is my choice for the stud threads.
     
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  5. Jul 8, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    On the bolt on the side it sounds like someone screwed it in too far maybe? Obviously it's into the water jacket. I'd go for a stud instead of the bolt and maybe Permatex on it too. With the head off can you see down in there?
     
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  6. Jul 8, 2019
    _fletch_

    _fletch_ New Member

    Kentucky
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    IMG_4111.JPG IMG_4112.JPG
    I'm referring to the valve cover on the side of the block. Here's a pic. In the second one you can see the blue RTV and coolant pooling beneath it.
     
    Last edited by a moderator: Jul 9, 2019
  7. Jul 8, 2019
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member

    Tantallon, Nova...
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    Yup, that ain't supposed to look like that. :(

    Glen's idea about the stud looks like a good bet.
     
    Last edited: Jul 8, 2019
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  8. Jul 8, 2019
    Keys5a

    Keys5a Sponsor

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    I've always had studs in these two positions. I neve knew they were open to the water jacket.
    -Donny
     
  9. Jul 8, 2019
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member

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    They're not supposed to be. :whistle:
     
  10. Jul 8, 2019
    PeteL

    PeteL Member 2020 Sponsor 2019 Sponsor

    Hills of NH
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    You should be very cautious about RTV like that. A gob of it could get loose and block an oil passage.

    I prefer Permatex.
     
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  11. Jul 8, 2019
    Greevesman

    Greevesman Member 2020 Sponsor

    Napa, Ca
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    What I was trying to say and have used is "Permatex High Temp Thread Sealer"
    It's fairly expensive if I remember correctlt.
    Look it up.
     
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  12. Jul 8, 2019
    _fletch_

    _fletch_ New Member

    Kentucky
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    Yeah, that's not my work. I've never seen RTV used in that kind of application. I'm going to remove it. Thanks.
     
  13. Jul 8, 2019
    _fletch_

    _fletch_ New Member

    Kentucky
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    So the consensus here then is to use Permatex #2 on the threads when I bolt everything back up and we'll be good to go? I'm notorious about overkill, but would filling those holes with a two part epoxy and re-drilling/re-tapping not be a better long term solution? How is Permatex #2 when it comes to getting things back off?
     
  14. Jul 9, 2019
    _fletch_

    _fletch_ New Member

    Kentucky
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  15. Jul 9, 2019
    _fletch_

    _fletch_ New Member

    Kentucky
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    Also, I believe what I'm getting from ya'll is that originally, these were all studs in the exhaust manifold and valve cover? Like I said, mine were bolts, and barely bolted at that, with three of them being broken off. I'll go ahead and get new studs, as I like that idea better.
     
  16. Jul 9, 2019
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member

    Tantallon, Nova...
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    No, the side valve cover uses a bolt in the front & a special screw in piece in the rear for the throttle linkage to swivel on. I'd go with the stud for the front, doesn't seem like the rear leaks so retain the throttle swivel.
     
  17. Jul 9, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    As far as Permatex #2 it's non hardening, but sets up enough to work good.
     
  18. Jul 9, 2019
    timgr

    timgr Eppur si muove. 2020 Sponsor 2019 Sponsor

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    I would test the depth you need for your stud, find your stud to go in there (Napa or even McMaster-Carr) clean good with a non-greasy solvent (in order of agressiveness - xylene, lacquer thinner, acetone, whatever you have) and put the stud in with Permatex #1. I think the #1 product will withstand the constant oil splash of the side cover better than #2, and will fill any voids a bit better than the thread sealer. Plus I keep a tube of #1 in my toolbox - handy stuff. It will harden rock-hard; I'd leave it open for a few days.
     
  19. Jul 9, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    I agree with Tim on the #1 for the side stud, that's one you definitely don't want moving at all.
     
  20. Jul 9, 2019
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    I use aerosol brake cleaner for degreasing things before using sealants or lock tite. The jet spray though a nozzle straw is very effective.
    -Donny
     
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