[william]

I had to remove the exhaust manifold on my 440, and one of the studs broke. I drilled it out and installed a heli coil, but it leaks coolant. What should I be using to "seal" this. I used permatex high temp thread sealer (what I use on my other studs), and it leaks like a tin goose. Is there a loctite product or metal epoxy I can jam in there to stop up the leaks? I am leaving on a 3500 mile trip with the truck next week, and I MUST get this fixed. Is this a lost cause, do I need to remove the head and take it to a machine shop? Any advice here would be much appreciated. Thanks,
william

 

[Smokey]

I've had good luck with JBWeld in water-proof-required settings...

So, you drilled out, and threaded in the helicoil to replace the threads back down to stock size stud, but the stud you screwed into the helicoil threads is not a tight fit ?

 

[william]

Yep, I drilled it out and used the heli-coil that would allow me to use the original size of studs (3/8 coarse). The stud is a tight once it is snugged in, but it still leaks. I am assuming that it is leaking between the coil and the head more than the stud and the coil. If that is the case, I might be SOL, because I cant remove the old coil, and I may have to install a new coil with the correct sealant (jbweld) in order to stop the leak. I am starting to wish I had left the broken stud in the head and listened to the exhaust leak.
I also need those long funny nuts used on the two inboard studs of the big block truck manifolds. Anyone know of a replacement? Mine are stripped. Thanks...
william

 

[macario]

Use permatex number 1 and let it set over night at least.

Did you replace the broken stud with a new one or used one?

Mac

 

[macario]

I can sell you a couple of the long nuts.

Mac

Yep, I drilled it out and used the heli-coil that would allow me to use the original size of studs (3/8 coarse). The stud is a tight once it is snugged in, but it still leaks. I am assuming that it is leaking between the coil and the head more than the stud and the coil. If that is the case, I might be SOL, because I cant remove the old coil, and I may have to install a new coil with the correct sealant (jbweld) in order to stop the leak. I am starting to wish I had left the broken stud in the head and listened to the exhaust leak.
I also need those long funny nuts used on the two inboard studs of the big block truck manifolds. Anyone know of a replacement? Mine are stripped. Thanks...
william

 

[TheRamChargerMan]

I would say it is the heli coil leaking against the head. Is there any way you can get some sealant in the hole past the heli coil insert like maybe put a glob in the hole and then run the stud in

 

[Smokey]

Yeah, sadly enough that's about all I can suggest too... Epoxy and pray.

 

[william]

I did manage to get the helicoil out, so I installed a new one with jb weld on it, and then jb weld on the stud as well. I let it set overnight,and I will try to cure it with some indirect heat this am.
I dont think I will put the nut on it to tighten the manifold (pushing my luck), I will just pray that the coolant doesn't leak. I will live with the exhaust leak for now I guess. Once I get to Halifax, I will pull the head and have it repaired at a machine shop. 72 hours before departure and I am still trying to get this thing fixed, never mind everything else that I need to do....
william

 

[macario]

Good luck on your trip.
When you get back, I found a couple of used barrel nuts that you can have for free if you want them. Threads appear to be good.

Mac

I did manage to get the helicoil out, so I installed a new one with jb weld on it, and then jb weld on the stud as well. I let it set overnight,and I will try to cure it with some indirect heat this am.
I dont think I will put the nut on it to tighten the manifold (pushing my luck), I will just pray that the coolant doesn't leak. I will live with the exhaust leak for now I guess. Once I get to Halifax, I will pull the head and have it repaired at a machine shop. 72 hours before departure and I am still trying to get this thing fixed, never mind everything else that I need to do....
william