Thread: Coolant leak from header bolt hole.

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I have a pair of World S/R heads. Now in the instructions, it says to use a thread sealer on exhaust bolts as the bolt holes intercept coolant passages on some of the holes..OK... I used Permatex liquid type with teflon...leaked,...tried the teflon pipe tape,...leaked. Is there any other sealers out there to use ? It stays good till it gets hot. I figure its melting the sealer being at the exhaustport. Think maybe a high temp RTV ? heck, I don't know, I'm disgusted. I am at the point of putting header studs in with JB Weld to stop it, but that's pretty drastic....HELP please. Called World,... they state the liquid stuff I used should seal it...it don't.

Originally Posted by Weasel Diesel

I have a pair of World S/R heads. Now in the instructions, it says to use a thread sealer on exhaust bolts as the bolt holes intercept coolant passages on some of the holes..OK... I used Permatex liquid type with teflon...leaked,...tried the teflon pipe tape,...leaked. Is there any other sealers out there to use ? It stays good till it gets hot. I figure its melting the sealer being at the exhaustport. Think maybe a high temp RTV ? heck, I don't know, I'm disgusted. I am at the point of putting header studs in with JB Weld to stop it, but that's pretty drastic....HELP please. Called World,... they state the liquid stuff I used should seal it...it don't.

Weasel, my front accessory drive package came with some studs that mount into the block, then have spacer nuts applying pressure to the water pump. The instructions from Rocky Hinge were to coat the threads on several studs with high temp RTV sealer as you said. I have not lit it off yet, but I'm hoping it works as instructed.

drain the coolant out or lower then heads .wash head bolt holes out with thinner and a bottle / gallery brush. when clean and dry use hi heat RTV should stop it. with world heads this is not uncommon .it will never seal up till clean and dry

rspears & Pat,... thanks. I went out, drained the coolant, Run a thread tap in it to clean out access teflon, 30 Qtips, and 2 brushes later, dried her out and used red HT silicone. Some in the hole end and coated the bolt well. I'm gonna let her set 2 days before refilling with coolant.

This past week has been a beast with this thing. We started out at a local box parts store asking for Fel pro 1003 head gaskets when we built her. I did not pay attention and they gave me 7733 gaskets, which is still for SBC. 2 weeks ago we developed an external coolant leak between the block & head. World told me that the 1003 was the only gasket to use on it. So, we got the 1003's, and a new set of ARP head bolts, and got that problem took care of. But these 2 bolts has whooped my butt. I hope it works, as I now have no more hair to pull out.

Well, the RTV seems to have taken care of the header bolt leak. Bad news, I'm still getting a coolant seep on the drivers head gasket at the rear of the head at the bottom. Not too bad, but it is there. Doesnt do it until system has a bit of pressure on it. I'm running a 7 lb cap. I cleaned everything off real good when I changed the gaskets, hmmm, I dont know. I havent ran her much, maybe I need to run it more and let the heat get to them to seal them better.

did you go and re Tq the head bolts ? what sealer did you use on your head bolts ? sure one is not wicking coolent threw the head bolt hole . try one of them small cans of alum dust sealer i use that on head stud blocks helps seal them

HMM, now that you mention it, it is right under the last lower head bolt... I used the prematex thread sealer on it, maybe tha actual threaded hole in the block is egg shaped or something. I'll try re-sealing it.

no that would be hard to do to have a threads egg shaped just try the sealer if the bolts are tq up right .to use the permatex s teflon the bolts must be very clean and block as well or it will rope off the threads .if coolant in the block you going to have to drain it all out then to wash the threads out with carb cleaner . clean bolt then put it back in .if you are sure that you tq all of your bolt buy a small tube of alum dust and add to the rad it will seal it less you want to do lot of work ? pulling all of them out one at a time and re sealing them less your sure that there is only one leaking

Moroso makes a ceramic coolant sealer that you add to the coolant and after running it and letting it cool you drain it.

What about the pellets GM used to put in the Cadilliac radiators?

Originally Posted by fun4me

What about the pellets GM used to put in the Cadilliac radiators?

that was for the the alum block with wet iron sleeves with rubber O rings that had a very poor design that would leak if you look at them wrong .engine were Junk ... the alum dust will work just fine or goodson and sliver seal sell pellets for re builds drop them in the block for the just in case deal . sealers are abit over kill i think for this if one head bolt is only leaking . he must of fixed it its been some time. the header bolts is a nother deal were world just drilled the ex bolts to deep and can seep if you read world tec sheet on there heads they tell you must use sealer on the ex bolts

I know what they were used for. GM still to this day recommends the pellets in some applications.

Originally Posted by fun4me

I know what they were used for. GM still to this day recommends the pellets in some applications.

OH i so sorry you knew thatnext time i try better to read your mine so i will not post something YOU KNOW