And so it goes

[Humpty]

Working on my 56 CJ5 and it's been a real thrill so far. Pulled real hard to the right when braking, minor exhaust leak, leaf springs that were not the right length (ride like a hardtail Harley)...number of small issues but the price was good and it seemed to be all there.
New braking system including dual master cylinder. Looks easy without the body on but a whole new challenge with it on. All the normal snakes like loose backing plates, leaking cylinders, seals installed wrong. I was thinking the guy who worked on this had a comic book instead of a shop manual. But got it done yesterday, took it for a drive and felt really good....except a exhaust manifold leak.
The stud at the back cylinder was stripped out and they had cooned in a allen head bolt with a half dozen washers to space it I guess. Not wanting to live with this I thought what the hay, let's fix this now. Maybe a stud insert and we're good to go.
Tore it down and when removing the back Allen head bolt a stream of coolant spews from the orifice. So Jughead must have cranked a too long fastener through the coolant jacket of my F head block.
It never ends sometimes....

[bmorgil]

Humpty, I am pretty sure that stud is wet (drilled through) this is how they were made on the L head block. I will bet it is the same on the F head block. You need to seal that thread that's all, if it is through drilled. If it was stripped, a good insert will do the trick. However, if it has good threads and they just took out the studs and put in Allen bolts your OK. If you look through my resto post, you will see I had a heck of a time with one of mine. It steamed no matter what I tried, because the threads were very badly worn. In the end after trying a lot of things, I settled on what my Machinists recommended. Black Silicone. Sealed it right up.

I think your OK Humpty.

[gmwillys]

All is good. The stud is wet by design, so add some pipe dope or Loctite thread sealant to the new stud and you'll be good to go.

[Humpty]

All is good. The stud is wet by design, so add some pipe dope or Loctite thread sealant to the new stud and you'll be good to go.

Well that's some great news! It is stripped so I'm going to throw an insert in it and lock it down.
Wow. I hardly slept last night and now I'm on cloud nine.

Thanks to both of you for your advice.

Steve

[bmorgil]

Humpty, Drain the water down well below the stud hole. You want those threads clean and dry. Very clean. After a thorough brushing with solvent, I use cotton swabs and rubbing alcohol until they come out of the thread hole clean. I would get the correct stud, washer and nut, and clean the stud also. Once the Anti-Freeze gets all over the threads, or machining oil, it is hard to get stuff to "stick". If you use silicone put it on the stud threads only. You don't want to get sloppy. It does not belong in the motor. Make sure you let it cure before refilling. In any event sounds like you are sleeping tonight!

[Humpty]

Excellent advice. I was going to run a little bore cleaner on a brass brush from my gun kits. Maybe something around 45 caliber and then start swabbing them out.
I have new studs and bolts coming from KW. Once cleaned up thought I would use red thread locker to secure the studs... looks like they only go in about 3/4 inch.
Do you happen to know the torque settings on the manifold bolts?
Thanks
Steve

[bmorgil]

The torque spec for the nut is 29 to 35 ft lbs. The stud goes in finger tight with sealant on the threads.

Perfect idea on the bore brushes! I have some small engine brushes that I use. I never thought of using gun rods! That would have been an awesome thing several times for several years, had I thought of that! I have just always had a rack of engine brushes.

Red LOCTITE is a good choice. It does require a fairly good thread fit or it might not seal. As long as you have a good fit it should work well. Definitely Red on your insert. If you can use an E-Z Lok style it would probably work best.

[Humpty]

Ya if you're careful you can chuck the brush in a drill...as long as you go slow you can spin the brush and really clean the threads. Bore cleaner, like hoppes, or even your preferred break free works good then blow it out with some brake cleaner.
Works for me.

[pelago]

ya if you're careful you can chuck the brush in a drill...as long as you go slow you can spin the brush and really clean the threads. Bore cleaner, like hoppes, or even your preferred break free works good then blow it out with some brake cleaner.
Works for me.

i use gun cleaning brushes a lot