leaking coolant around head bolts

[ted vitale]

Wc-51 leaking coolant around head bolts, could this be threads are not sealed?

[Cheyenne Dave]

No...the undersides of the bolt heads are leaking where they contact the head. You should retorque the head bolts , in sequence and see if that cures your seepage.

CD

[Matthew Ziegler]

head bolts

just curious are they bolts, most came with studs. I'd recommend draining the coolant, removing the bolts, coating the threads with pipe dope, reinstall and re torque the head, also pull the plugs and crank it over to make sure no coolant wound up in the combustion chamber. better to be careful these things aren't cheap or easy to find.

[Cheyenne Dave]

just curious are they bolts, most came with studs. I'd recommend draining the coolant, removing the bolts, coating the threads with pipe dope, reinstall and re torque the head, also pull the plugs and crank it over to make sure no coolant wound up in the combustion chamber. better to be careful these things aren't cheap or easy to find.

It is much cheaper ( Free, actually ) to simply re torque the head and observe if you have stopped the leak(s). Your service manual will give recomemded torque values for both bolts and stud nuts...yes, they have different values.

C.D.

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[Charles Talbert]

May be cheaper now, BUT the smart thing to do is pull the bolts, clean the threads, apply high temp thread sealant, reinstall the bolts torqueing in sequence to the recommended 65-70 ft. lbs.

Re-torqueing the bolts usually doesn't work to stop a leak. Actually if the threads are not sealed, 99% of the time, leaks will result. I learned years ago to always seal bolt or stud threads. Can't recall ever having a leak since we started doing that. Another problem is this; Sometimes there will be cracks between the bolt holes in the block and the water ports which will be the source of such small leaks. Most often if the bolts threads are sealed with a high quality high temp thread sealant, it will stop the leak and most often the tiny cracks never become an issue. What I'm saying is slowing a leak isn't what you need to do; stopping it is the key point.

[DrPepper]

Mr Talbert has it right...

In particular use Permatex Aviation Form-A-Gasket #3. It is the ONLY thing I use on threads going into a block. Sticks to the threads and acts as a sealant and anti-seize because it never really hardens. Looks like Molasses and about the same consistancy, gets on everything.

http://www.permatex.com/products/Aut..._Sealant_a.htm

You do not want plumbers pipe dope or any RTV for this application. The stuff is a mess to work with and you will cuss getting it off your fingers but...it works.
IMHO,
DrPepper

[Charles Talbert]

Dr Pepper; Don't connect my name to this product

In particular use Permatex Aviation Form-A-Gasket #3. It is the ONLY thing I use on threads going into a block. Sticks to the threads and acts as a sealant and anti-seize because it never really hardens. Looks like Molasses and about the same consistancy, gets on everything.

http://www.permatex.com/products/Aut..._Sealant_a.htm

You do not want plumbers pipe dope or any RTV for this application. The stuff is a mess to work with and you will cuss getting it off your fingers but...it works.
IMHO,
DrPepper

What you need to use is high temp thread sealant. Aviation Form a gasket is from the dark ages when it comes to today's sealing technology. It is also a heck of a mess to clean up if future disassembly is necessary for any reason.

High temp thread sealant is available from both Permatex and Lock-Tite brands. The tube is white with red lettering from either brand, and are the only products I personally recommend for thread sealing.

I have no use for Aviation Form a gasket on anything, the days of this type sealing technology are gone.

[DrPepper]

Hi Charles....

OK, You do NOT recommend the product I showed..!!!

I tolerate my dirty fingers to get the job done the way I am used to...LOL
Standard old #3 is good to 400F, If the engine goes to 400F it's all over anyway.

I think I FOUND IT...!!
http://www.permatex.com/products/Aut...ad_Sealant.htm

Never to old to learn something new. I guess I will have to go look for this to give it a try.

Thanks and sorry for the misunderstanding
DP

[Charles Talbert]

No need for any apology, you can use whatever you like.

The Permatex link you posted is what we use and like so well.

[Cheyenne Dave]

May be cheaper now, BUT the smart thing to do is pull the bolts, clean the threads, apply high temp thread sealant, reinstall the bolts torqueing in sequence to the recommended 65-70 ft. lbs.

Re-torqueing the bolts usually doesn't work to stop a leak. Actually if the threads are not sealed, 99% of the time, leaks will result. I learned years ago to always seal bolt or stud threads. Can't recall ever having a leak since we started doing that. Another problem is this; Sometimes there will be cracks between the bolt holes in the block and the water ports which will be the source of such small leaks. Most often if the bolts threads are sealed with a high quality high temp thread sealant, it will stop the leak and most often the tiny cracks never become an issue. What I'm saying is slowing a leak isn't what you need to do; stopping it is the key point.

So Charles, you are against an exploritory operation as simple and free as re-torqueing, as a diagnostic tool?

Further more you are advocating pulling all the head bolts and re-using the old head gasket, and not chasing the bolt tappings? Pretty shoddy mechanic practices if you ask me.


C.D.

[Charles Talbert]

This is almost laughable

Once again, I'll try to explain what I really mean instead of allowing readers to go on your assumptions of what I mean. I didn't say anything about removing the head, or all the bolts at once. I do see where you are headed though and why.

Common sense must kick in. Drain the cooling system. Removing the bolts in proper sequence, cleaning, chasing threads in the deck, and reinstalling the bolts with high temp thread sealer on the threads one at a time is fine and stands a good chance of stopping a leak, even in an old installation. It is a common fact that coolant will leak readily past unsealed threads, and re-torquing all day long won't stop it from coming around the bolt head if the fluid source is at bolt threads. There is no seal around the head of the bolts (or nuts in the case of studs), so if fluid is there, (directly under the bolt head) it will come out. 3 sources of a coolant leak can exit around a head bolt, #1 and most likely, unsealed bolt threads, #2 a gasket leak that is allowing coolant to escape into the area of a bolt passage, #3 a crack in the head that has come through to a bolt passage. Since unsealed threads is by far the most common cause of leakage around bolts, common sense says seal the threads first. If there is only 1 bolt that is showing a leak, remove, prep and reinstall that bolt only; if the leak is coming past threads because of no sealer, issue will be cured. Another real issue with attempting to retorque a bolt is the greater risk that it could break off during the retorque attempt if rust corrosion has attacked it. Removing it is far less likely to break a bolt than attempting to pull it tighter. If the leak persist, then look at one of the other possibilities I mentioned. If the head has to be removed in order to locate and correct the leak source, then yes Dave I would certainly advise replacing the gasket upon reassembly; you have never heard me make a recommendation to reuse a head gasket. I would also suggest resurfacing the head and carefully checking the deck surface to be sure all is in line there, as it may possibly need to be surfaced also in order to correct the leak. By all means as I believe Matthew suggested, if possible source #2 or #3 is found to be in play, check closely to be sure no coolant is escaping into a combustion chamber, that is immediate bad news that will need to be investigated very conclusively.

Dave, to me your intentions are beginning to look pretty obvious this afternoon. You have become aggrevated at me because you feel I insulted your friend in another thread, so you are barring no holds on striking back with force. Some things in life are just too obvious, but apparently you haven't noticed that. Don't think I've ever experienced a moderator on any site going off in such a direction.

You have chosen to label our practices as being shoddy, feel free and talk all you want. You need to come on over to NC and check out our practices; we have never turned anyone away who desired to come by, happy to have you as well. It is blantantly obvious that you haven't even begin to scratch the surface of the precision practices that go into the components and projects that go out our doors. I know you know the kind of workmanship we offer here; that's why your direction this afternoon is so obvious.