Author Topic: Need to get rid of a pesky header leak?  (Read 2300 times)

Offline 1979C20

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Need to get rid of a pesky header leak?
« on: May 02, 2011, 04:54:20 AM »
Ive been fighting an irritating header port leak for quite a while. And I finally decided enough was enough. My gaskets kept blowing out due to warped flanges. So, I went old school sprint car days on it. Now, as part of my exhaust leak fix, I had to do some welding, Because my mufflers had no support and just dangled about and eventually cracked along the bottom.



Thanks Dad!

I also discovered why they are so craaaaapppy.


Anyways, to fix your header leak, you need a tube of high temp RTV. The clear RTV sets faster but any color will work. You need to put a bead around your header port about 1/4 to 3/8ths inch thick. Put it on and let it sit. once the silicone is dry enough to touch with out it sticking, flatten out the bead a bit with your finger. Then let the silicone set for like 3 hours. Once it is hard, slap the headers back on and tighten the bolts. It should last the life of the headers. You will not need to re-tighten them later and they are reusable.


A bit thicker than this, I added some more after this picture.



I also snapped a couple of pictures of my actual full exhaust because I was bored.



This can help show the bends needed to go over and under the crossmember.


The bottom muffler on the last picture goes towards the transmission on my truck, and only slightly up/down. Both of my mufflers are equal length, parallel to eachother, parallel to the frame, and parallel to the ground.

After siliconing around the header ports, I have not leaked ANYTHING from the headers. And my truck doesnt backfire anywhere near as much. I have ZERO exhaust leaks now.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline bake74

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Re: Need to get rid of a pesky header leak?
« Reply #1 on: May 02, 2011, 03:12:59 PM »
     Your nose and mostly your brain will thank you.
#1: The easiest and most obvious solution to any problem is 99% of the time correct.
#2: There is no such thing as impossible, it just takes longer.
  74 k10, 77k10    Tom

Offline beastie_3

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Re: Need to get rid of a pesky header leak?
« Reply #2 on: May 02, 2011, 06:05:07 PM »
did you support the rear of the pipes after? i didnt see if you wrote that or not.

Ive heard of RTV for gaskets before, good thing I didnt try it because I wouldnt have done it that way haha.

Offline 1979C20

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Re: Need to get rid of a pesky header leak?
« Reply #3 on: May 02, 2011, 10:27:11 PM »
I forgot to mention that, the driver side muffler is held up buly the crossmember and the passenger side has a chain link welded onto the end and I put a big heavy duty spring onto that link and attached the other side to one ofbthe parking brake eyelets that are rivited to the frame. Iglt pulls it up, and toward the back of the truck, so it should work okay.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline snibook7537

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Re: Need to get rid of a pesky header leak?
« Reply #4 on: May 03, 2011, 12:06:29 AM »
I can't wait til I fix my leak, I have a bunch of cracks in my manifold and the thing backfires like no tomorrow sometimes.  Theres a giant fireball out the back if you do it right.  Pretty cool at first now just waiting to get pulled over for it. 
1984 Fiero se pwr windows Holley TBi, cam, 86 5spd
1987 GMC V3500 350 TBi 4spd 205 t-case

Shoulda never sold:
1976 c-10 beater 250-6 4spd no pwr steering, brakes. Recycling truck

Offline Irish_Alley

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Re: Need to get rid of a pesky header leak?
« Reply #5 on: May 03, 2011, 09:25:33 AM »
So your pipe is just sitting free on the cross member free to rub back and forth free to bounce up and down. You should hang it some where
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