Exhaust Header Bolt -Leaking coolant

scaputo3 · Dec 10, 2016

I know that driver side rear 2 bolts sometimes leak coolant ( or at least other have told me). I removed my passenger side, third forward bolt and it leaked like the devil. Is this normal? If a problem , how bad? Car runs solid. Never saw any coolant in the oil.
I have a 1976 440 RB.

Thanks for your help

HEMI-ITIS · Dec 10, 2016

Exhaust bolts are wet.You need to seal them when they go in. :thumbsup:

scaputo3 · Dec 10, 2016

HEMI-ITIS said:
Exhaust bolts are wet.You need to seal them when they go in.

scaputo3 · Dec 10, 2016

Thank you. Is it normal for coolant to circulate around that area of the block?

black64 · Dec 10, 2016

Coolant circulates through heads in that area. Make sure you drain the coolant low enough to clean the threads and put sealant on the bolt and let sit for 24 hours for sealant to cure before adding coolant and running engine.

HEMI-ITIS · Dec 10, 2016

YES!! That why you need to drain as said.

scaputo3 · Dec 10, 2016

Thanks very much!

moparjohnny · Dec 10, 2016

scaputo3 said:
Thanks very much!

what kind of sealant.

OH71RRunner · Dec 10, 2016

I've used Teflon tape, the gray pipe thread sealer, silicone. The best results for me was the thread sealer.
What worked for me may not work for you. Others have had success with different things and differing opinions on all things tried.
Just make sure the threads and bolts are clean AND dry before you try anything.
Good luck.

RJRENTON · Dec 20, 2016

I is my suggestion that AFTER the coolant is drained below the level of the heads, and after removing the stud, to tap the hole to clean it up and remove the crud. Purchase new studs from a Mopar source for the correct location. NOTE THAT THERE 2 DIFFERENT THREAD SIZES...THE ONE IN THE HEAD IS DIFFERENT THAN THE EXTERNAL PART OF THE STUD (the part where the barrel nut screws over). When ready to assemble, I always use a LOCTITE product....a thread cleaning material followed by (my choice is Red hydraulic sealant or Red thread lock...all applied sparingly per instructions and installed with stud installer and tightened to 20 ft pounds torque. Loctite products are anaerobic sealants...they cure WITHOUT AIR. LOCTITE material is avaliable at most autopsies houses...NAPA is a good starting point. DO NOT USE TEFLON TAPE OR PIPE JOINT COMPOUNDS . If you use the LOCTITE PRODUCTS THERE WILL BE NO LEAKS BUT FOLLOW THEIR INSTRUCTIONS.....
But this is just my opinion.....I'm sure that there will disagreementstill.
Cheers
RJ RENTON

scaputo3 · Dec 20, 2016

RJRENTON said:
I is my suggestion that AFTER the coolant is drained below the level of the heads, and after removing the stud, to tap the hole to clean it up and remove the crud. Purchase new studs from a Mopar source for the correct location. NOTE THAT THERE 2 DIFFERENT THREAD SIZES...THE ONE IN THE HEAD IS DIFFERENT THAN THE EXTERNAL PART OF THE STUD (the part where the barrel nut screws over). When ready to assemble, I always use a LOCTITE product....a thread cleaning material followed by (my choice is Red hydraulic sealant or Red thread lock...all applied sparingly per instructions and installed with stud installer and tightened to 20 ft pounds torque. Loctite products are anaerobic sealants...they cure WITHOUT AIR. LOCTITE material is avaliable at most autopsies houses...NAPA is a good starting point. DO NOT USE TEFLON TAPE OR PIPE JOINT COMPOUNDS . If you use the LOCTITE PRODUCTS THERE WILL BE NO LEAKS BUT FOLLOW THEIR INSTRUCTIONS.....
But this is just my opinion.....I'm sure that there will disagreementstill.
Cheers
RJ RENTON

Thank you

dan juhasz · Dec 22, 2016

Permatex makes a specific thread sealant that I use in the shop for any wet bolt application. WHite tube, think it says Teflon thread sealant. Apply to chemically cleaned threads, let them set up and install.

Funship32 · Dec 29, 2016

I've used non-hardening pipe dope with good results as it resist leaking and pressure.

RJRENTON · Dec 30, 2016

Funship32 said:
I've used non-hardening pipe dope with good results as it resist leaking and pressure.

Sir,
I disagree with your premise of using pipe dope as a sealing compound on bolt or stud threads. Pipe dope or pipe thread sealing compound works becsuse the pipe thread is tapered whereas the bolt thread is not. The pipe dope will just fill in the voids between the male and female threads of the connecting parts but due to differential expansion between the two, there exists the potential for lesks. For my money and effort, I'm using an anaerobic sealant as noted. But this is just my opinion.
Bob Renton

scaputo3 · Dec 30, 2016

Thanks. What is an example of an anaerobic sealant?

Fran Blacker · Dec 30, 2016

scaputo3 said:
Thanks. What is an example of an anaerobic sealant?

See post #10 he explains it there.

Funship32 · Dec 31, 2016

RJRENTON said:
Sir,
I disagree with your premise of using pipe dope as a sealing compound on bolt or stud threads. Pipe dope or pipe thread sealing compound works becsuse the pipe thread is tapered whereas the bolt thread is not. The pipe dope will just fill in the voids between the male and female threads of the connecting parts but due to differential expansion between the two, there exists the potential for lesks. For my money and effort, I'm using an anaerobic sealant as noted. But this is just my opinion.
Bob Renton

Well, Bob, you can disagree with my premise. However as with your opinion I too hold an opinion and my opinion is that I have used pipe dope/sealant with good results. However in order to eliminate confusion for the person who is trying to seal his leak and to clarify my position: I use Rectorseal tplus2 sealant ( http://www.rectorseal.com/rectorseal-t-plus-2/). I used it due to the info about it: "RectorSeal® T Plus® is a non-hardening thread sealant containing PTFE plus synthetic fibers. These fibers dispersed in a resinous base combined with inert mineral fillers provide maximum sealing performance. Its low coefficient of friction allows tighter joint makeup with lower torque. It also breaks out easily without galling, seizing, or damaging threads. It is excellent for service where immediate pressurization is necessary". So ultimately, it boils down to what people use and have success with. Some use Teflon tape, some use silicone, some probably rub dirt on the threads. Opinions vary and so do results. All I can do is offer my own experience which is- I've had good experience with the Tplus2 pipe sealant. Also it can be had at the local home despot or Ace hardware store and at $4 a tube it won't break the bank.

scaputo3 · Dec 31, 2016

Funship32 said:
Well, Bob, you can disagree with my premise. However as with your opinion I too hold an opinion and my opinion is that I have used pipe dope/sealant with good results. However in order to eliminate confusion for the person who is trying to seal his leak and to clarify my position: I use Rectorseal tplus2 sealant ( http://www.rectorseal.com/rectorseal-t-plus-2/). I used it due to the info about it: "RectorSeal® T Plus® is a non-hardening thread sealant containing PTFE plus synthetic fibers. These fibers dispersed in a resinous base combined with inert mineral fillers provide maximum sealing performance. Its low coefficient of friction allows tighter joint makeup with lower torque. It also breaks out easily without galling, seizing, or damaging threads. It is excellent for service where immediate pressurization is necessary". So ultimately, it boils down to what people use and have success with. Some use Teflon tape, some use silicone, some probably rub dirt on the threads. Opinions vary and so do results. All I can do is offer my own experience which is- I've had good experience with the Tplus2 pipe sealant. Also it can be had at the local home despot or Ace hardware store and at $4 a tube it won't break the bank.

This is all great information. Thank you guys very much. Have a great new year

khryslerkid · Dec 31, 2016

Here is what an old fart like me has been useing for many years, before silicone was ever invented, before any of these ten letter, four syllable worded compounds were even developed, and it has always worked. If the threads are a little wet, it sticks and seals. If it's in contact with coolant or oil, it's not going to deteriorate. When it comes time to disassemble it's still soft. It's older than me and you can buy it anywhere.

mopar 3 B · Dec 31, 2016

If you all have not noticed there is a tapered seat on stud bolts and if torqued correctly should should require no sealant. I add a good water cure silicone just for insurance. The less applied the better silicones are not gap fillers. Header bolts will always require a sealant do to the lack of the seat.
But use what ever sealant works for you or trips your trigger. Some of us do not have a 24 hr. waitng time for assembly.

Exhaust Header Bolt -Leaking coolant

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