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Leaking head stud

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jgodfrey View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Topic: Leaking head stud
    Posted: 22 Apr. 2021 at 1:16am
Freshly rebuilt L134 on my '46 CJ2A.

I've been running it to get it to temp, adjust timing, check the oil pressure, and look for leaks.

I have a couple small oil leaks to address in the oil filter fittings and oil pan.  But today when it was running I saw liquid seeping up through the number 1 head stud.

It was slow but ran down into the spark plug well within a couple minutes. 
It doesn't feel oily, but it also isn't really green.

I ran the engine at least 5 times before this getting it to temperature with no issues. Last Sunday I retorqued all of the nuts in the correct pattern to 65ft lbs.

I retorqued number one again and it still seeped. Before it was at idle, and now it is only at an increased rpm.



What do I do next? Retorque everything? Loosen everything and put a sealer on the studs?

Again, this is new territory for me.

Thanks
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captianpattson View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote captianpattson Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 1:33am
If you determine that it is coolant coming up from the block but only a small crack be careful with sealant as you can hydro lock down in the block and blow out the bottom of the hole into the water jacket. 
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Post Options Post Options   Thanks (1) Thanks(1)   Quote JohnB Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 2:21am
If it's only seeping under the nut it will probably rust shut and stop leaking. But you have to leave it alone. 
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Bruce W View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Bruce W Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 2:21am
Were the threads of the studs coated with sealer (Permatex #2 is the favorite) before they were installed in the block? Whether they were or not is a moot point now. Put some good cooling system sealer in it.
BW

Originally posted by captianpattson captianpattson wrote:

  "you can hydro lock down in the block and blow out the bottom of the hole into the water jacket."

  ConfusedAll of the head stud holes go through into the water jacket already.LOL
BW


Edited by Bruce W - 22 Apr. 2021 at 2:27am
It is NOT a Jeep Willys! It is a Willys jeep.

Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You!

We Have Miles to Jeep, Before We Sleep.
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Ron D View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Ron D Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 2:44am
Just curious, but is the stud short? I always thought there's supposed to be a couple two or three threads showing above the nut to ensure proper engagement? Like the one to its left in the photo.

That might be urban jeep legend or b.s., I know not which.


Edited by Ron D - 22 Apr. 2021 at 2:50am
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jgodfrey View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 3:20am
I thought the same thing about the length of the stud. I was told by the rebuilder that it was fine.

I'd love to get other opinions though.

As far as next steps, I know there is a pattern for tightening and loosening these nuts, which I did when I retorqued them. But do I need to loosen them all to put sealer on this nut?

And while we're on that subject, should I do them all? Is this good old #2 non-hardening Permitex?  What part do I seal? Did I cause this by retorquing? Now that I think about it, it may not have completely cooled down when I did it.  It wasn't hot, since I could touch everything, but it also wasn't cold.

Sorry for the rapid fire uncertainty on this one, but I always get better answers here than Google

Thanks

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Post Options Post Options   Thanks (1) Thanks(1)   Quote Vintage Don Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 3:29am
I have experienced the identical problem. It never rusted shut. I did way too much work trying to fix it, with limited success. Got tired of taking the Head on and off...

I'm definitely not saying the following is an "approved procedure" - but I finally did this:

Drain the coolant. Weld the top of the stud and the nut together (usually more than once on something like this, to get a weld to truly "bite in" and hold) - so that unscrewing the nut brings the stud out with it. Get a new stud and nut. Put way too much thread sealant on it, and put it in there, torquing to 65.

Leak stopped.




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Post Options Post Options   Thanks (1) Thanks(1)   Quote Ron D Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 3:34am
I was taught that you can loosen, remove, replace, re-seal, and tighten one stud at a time all you want with no detrimental effect. Some I've heard say you can do it safely for 2 or 3 at a time, even if they're side by side. But if you loosen them all --- it's a new head gasket. I'm a learning rookie, and don't know if this is urban jeep legend or b.s..........good luck!

All head studs on the L134 penetrate the water jacket and are supposed to be sealed on assembly. Says so in the manual. The manual is my friend.

I've also heard that if anybody ever put a helicoil under that stud in the block (which is an ok repair if done properly) requires that the helicoil be sealed with permatex when installed, and then the stud also has to be carefully sealed with permatex when installed.


Edited by Ron D - 22 Apr. 2021 at 3:44am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 3:54am
Ok. So since I witnessed it coming up the center of the stud and then running down the side, can I take just that nut off and try #2 non-hardening Pemitex and retorque the nut?

And does the block need to be completely cooled when torqued? This didn't leak until I retorqued them. However I was doing a higher RPM run this time.

Thanks 
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Ron D Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 4:01am
The permatex going on the block end of the stud not the nut end means removing the stud to clean and seal that end.

And if it was me pulling that stud I think I'd spend $3 and find a longer one that leaves a couple 2 or 3 threads showing after torque. I might also wonder if there's a helicoil under it. Just my 2 cents.

Then I'd dip my finger in the permatex and smear it on all the threads of that stud going into the block. Not gobbed or dripping, just a good coat. Then I'd run the stud into the block as far as I could with fingers, back and forth up and down once or twice, then remove it and put a little bit more on the threads and run it back into the hole the last time. The stud needs to be "seated" in the block but not overly tight like with a wrench. Let it sit a few minutes for the permatex to cure a bit, then install the nut and grab the torque wrench. The nut and nut end of the stud is supposed to be clean and dry to get correct torque. But that's just how I'd do it.

I heard that the re-torque after initial run-in is supposed to be done on a "warm" engine.....not too hot, not too cold, but just right. Don't ask me what that means Papa Bear.

Let us know how it goes. Good luck!


Edited by Ron D - 22 Apr. 2021 at 4:35am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 4:36am
I wasn't planning on pulling the stud if I can avoid it. That would mean pulling the head, right?

Based on everything said here so far it seems that I could try to remove the nut, clean it up, and get some #2 permitex on the threads, then retorque?

I wish that stud was a little higher but there are a couple others like that and so far they are not leaking. So fingers crossed.

Here is a picture of the head right after I pulled it. They said there weren't any cracks or repairs on the head or block. It looked brand new before it was assembled. 


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Post Options Post Options   Thanks (1) Thanks(1)   Quote Ron D Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 4:38am
I'm pretty sure you can remove and replace one stud with no need to pull the head. But that's just me.

Did you see my post......

I was taught that you can loosen, remove, replace, re-seal, and tighten one stud at a time all you want with no detrimental effect. Some I've heard say you can do it safely for 2 or 3 at a time, even if they're side by side. But if you loosen them all --- it's a new head gasket. I'm a learning rookie, and don't know if this is urban jeep legend or b.s..........good luck!

Need one of the jeep doctors in this great forum to confirm my theory?

Good luck with trying to seal the nut end of a head stud against the water jacket. Band-aide if you ask me.


Edited by Ron D - 22 Apr. 2021 at 4:43am
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Bruce W Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 4:55am
  The stud needs to be sealed where it enters the block. I don't think sealing the nut threads will do any good. You will have to remove the stud to clean and dry both it and the threads in the block. You might be able to do this without removing the head. If the studs were not properly sealed in the block, you may have more just waiting to leak. Whether you take it out and seal it or not, drop a couple of these in your radiator and you leaks will stop. Contrary to what others may (will) say, it will do no harm.


BW
It is NOT a Jeep Willys! It is a Willys jeep.

Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You!

We Have Miles to Jeep, Before We Sleep.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 5:06am
Sorry. I did read your post, a couple times.  But I'm exhausted and I think my reading comprehension is down a few notches tonight. I'm frustrated by these leaks. 

I misread it, thinking you were talking about the nut end of the stud.  It makes sense now. A band-aid on this project isn't appetizing, since I've tried to do everything else the right way. 

I can't double nut that stud,  so I'm hoping it being a fresh rebuild will make it easy to remove. 

And yes, I'm hoping I don't see this anywhere else. But odds are, I will. 
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Ron D Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 5:50am
No worries J.

Better get to it before it rusts in place. Take the nut off and give it a little shot of PB Blaster or your sauce of choice to soak a bit and it should come out nice with a stud remover. You'll know pdq one way or another. Let us know how it goes!
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Ron D Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 6:08am
And don't forget to drain the coolant out of the block and disconnect your battery before doing it.

Good luck!
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Post Options Post Options   Thanks (1) Thanks(1)   Quote cpt logger Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 6:56am
Yes, rent or borrow a stud puller. Many (FLAPS), Friendly Neighborhood Auto Parts Stores, will loan you one. Most require a cash deposit when you borrow it, but the deposit will be returned upon return of the tool. Ask.

Pull the one stud. Clean the hole out with alcohol, acetone, or MEK. Then reinstall the stud with #2 Permatex. Torque it right away. Let it sit for a day, then warm the engine up to temperature. After it cools down re-torque this stud.

Remember to install the stud with the threads sticking out two more threads. I doubt that the stud is too short, it is probably just installed too deep. If you are nervous about just installing the stud a little shallower, buy one 1/4 inch longer.

It is industry standard to have one to three threads showing above the nut. That way you are using the correct amount of threads on the nut. Right now you are at least one thread shy what the Willys engineers wanted. It would probably be OK, but why risk it?

IHTH, Cpt Logger.
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Post Options Post Options   Thanks (2) Thanks(2)   Quote smfulle Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr. 2021 at 2:55pm
Not sure why Bruce's advice about cooling system sealer is being ignored. It requires zero wrench work and will fix the issue and prevent any other studs from leaking. My recent engine rebuild had six leaking studs. Poured in two little tubes of Alumaseal and problem solved. 
Lots of people think cooling system sealers do harm, but I haven't seen it.
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