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Old 09-19-2015, 04:08 PM   #1
merlin3
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leaking headers

when replacing my new failed starter i noticed my headers are leaking these headers are designed not to use gaskets but they leak everywhere i am trying to get to the shop for a complete exhaust is there any thing i can use? gasket sealer? i tried copper header gaskets and they still leak.thanks
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Old 09-19-2015, 04:14 PM   #2
GASoline71
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Re: leaking headers

The main thing that makes headers leak is over tightening of fasteners. Once the flange on the collector and the flange on the head are warped they will leak like crazy.

What brand of headers? Are they a ball and socket design on the bottom collector? Use a thicker gasket for the head flange and tighten from the inner 2 siamesed tubes outward.

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Old 09-19-2015, 06:37 PM   #3
merlin3
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Re: leaking headers

they are not the ball and socket style.they leak on the head,i will try different gaskets, they are Sanderson headers and i made sure not to over tighten the head flanges, i thought the copper gaskets were the best? thanks
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Old 09-19-2015, 08:26 PM   #4
TobyArnot
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Re: leaking headers

According to the Sanderson Website, they recommend using no gasket, just RTV sealant. That won't matter if the flanges are already deformed. Just my 2cents worth!
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Old 09-19-2015, 08:45 PM   #5
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Re: leaking headers

I have Sanderson shorty headers on my truck (I believe CC11?) and they have never leaked. I use the black RTV as they suggest (I think thats what it was, been so long). I put a little bit on the ends of the header bolts too and they've never backed off. I repainted my engine after taking it out to fix a couple oil leaks, I scraped the old black RTV off, applied new, put the header on a little more than finger tight and then went back out the next day and tightened them more. Never had an issue. Now I don't think you have to wait 24 hours to tighten them back up, but it's worked both times I've done it and never had any issues at all.
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Old 09-21-2015, 08:40 AM   #6
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Talking Re: leaking headers

I have used the replacement manifold gaskets that come with a standard rebuild kit(the perforated metal/composition type) with good results, the factory never used gaskets on the manifold to head surfaces. I stopped using header gaskets long ago, no sure fire way to keep them from blowing out. I work for a utility company and we have a gasket material called "Grafoil" like graphite gaskets with a wire screen impregnated inside, I'm going to try and make a set of these and see how they do, problem is, this material is prone to splitting when punching out holes, almost have to use a hole saw to cut it without tearing/splitting....will keep everyone posted on how it works out.
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Old 09-21-2015, 12:36 PM   #7
leftybass209
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Re: leaking headers

When you say you "made sure" you didn't over tighten them, did you use a torque wrench? There's a fun little game to play on people in shops that don't use torque wrenches: have them tighten 4 bolts with a ratchet to what they feel is the same torque spec. Then have them verify with a torque wrench. None of the bolts will be tightened to the same spec.
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Old 09-21-2015, 05:34 PM   #8
merlin3
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Re: leaking headers

thanks bigmike i will try that,leftybass thats a good point but how does one get a torque wrench on those header bolts?
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Old 09-21-2015, 07:27 PM   #9
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Re: leaking headers

some times if you separate each runner from the others at the head flange by cutting out the section of the flange between runners. you can minimise and even eliminate the effect of warping.and if only one runner/flange is warping it does not influence others.

its the heat that warps them. it also causes hardware to loosen up. when that happens people will go in and snug the hardware up, often while the header is too hot to touch.

wait until the header is cool to the touch, torque it properly, and use safety wire on your hardware to maintain that torque. If it is found to have loosened up, back the bolt off, retourque it and safety it up. done right, eventualy the header will stabalise and the bpoblem will go away. crank on it wrong and not only will those problems remain but improper torqueing on hot parts will cause several other problems as well.
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Old 09-23-2015, 05:16 AM   #10
snipescastle2
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Talking Re: leaking headers

using a "Crow's Foot" is about the only way to get in between the tubes to torque them down, if you can at all.....Ben
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Old 09-23-2015, 08:26 AM   #11
special-K
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Re: leaking headers

I have never torqued headers and don't have issues with headers leaking. The cheap gaskets they always gave you didn't help, so I used to have to tighten them from time to time on a couple trucks. The headers that are on my '72 I have now I installed in '01 and have yet to touch them. The exhaust system I had made at that time is showing it's age. One rear bracket weld broke loose and one side rusted off at the muffler. I have that coupled together, but time to think about new exhaust. I guess I'll go ahead and replace the headers while I'm at it.
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Old 09-23-2015, 11:18 AM   #12
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Re: leaking headers

I had issues with leaking header gaskets ended up putting two gaskets together then fitting no problems now
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