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Exhaust woes!

Discussion in 'The Garage' started by ecameron87, Dec 20, 2005.

  1. ecameron87

    ecameron87 1/2 ton status

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    About 10-12 months ago I rebuilt the exhaust on my 72 K5. I installed Hooker headers and Flowmaster Delta 40's. It is dual exhaust with 2-1/2 inch pipe.
    As you can guess, I cannot get the headers to stop leaking and it is very loud! I have tried Percy aluminum, copper, cork, paper, and pure silicone for gaskets. It didn't leak when I had manifolds. I am now using OEM original manifold gaskets with "Red" high-temp silicone. This last fix works better, but still leaks.

    My question is, what methods do you guys use to find where the leaks are coming from? Does anyone else have any more techniques for leaky headers that I haven't tried?

    I have searched the forums and have seen this problem everywhere, but nobody comes back and tells us what cured their leaks.

    I am at wits end with this thing and am ready to go back to manifolds unless someone has a miracle cure.
     
  2. danny7139

    danny7139 1/2 ton status

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    Have you checked the headers for warping? I know headers leak fairly easy, but I've found that copper gaskets with [SIZE=-1]some rtv high temp copper sealant fixxes the problem.[/SIZE]
     
  3. erik59

    erik59 Registered Member

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    Have you checked to see if all the welds on the collectors are fine. I have never had a problem with percy's stuff. I have used them all and they were the only ones that would work on my Mustang GT. I would say that they are warped or they are leaking at a weld before I would say it is the gaskets. Are the bolts staying tight? Stage 8 makes locking header bolts.
    Since it is a 72 I would use a gasket buffer and clean up the mounting areas of the header and head since you have had so many gaskets on it.
    Just my .02

    Erik
     
  4. stayaway

    stayaway Registered Member

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    double the gaskets always worked for me 2 gaskets per each header
     
  5. 89K5guy

    89K5guy 1/2 ton status

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    I always cut away the extra steel btween the exhaust ports so each one will seal individually to the head.I also use stock exhaust manifold gaskets (FEL-PRO)and have never had my headers leak.Good luck!:D
     
  6. ecameron87

    ecameron87 1/2 ton status

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    I have the felpro stock exhaust manifold gaskets on right now with high temp red silicone on them. I might try cutting the flange up as well. Any other ideas? Anyone know how to find where the leak is coming from?
     
  7. Cornfield creations

    Cornfield creations 1/2 ton status

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    make sure the heads are dead flat and so are the headers, if not then they will always leak. GM makes a stainless steel manifold gasket, it is a 2 or 3 layer gasket and will not rust. I have never had them go bad. Try those because I would not use anything else. Any GM parts guy that knows anything knows about them. Since headers like to come loose use the stage 8 locking header bolts.

    If you feel like it isn't the header on the head, check the collectors. Sometimes with collectors when you torque on the engine the collector will separate some and get loud. As far as the rest of the system we always use muffler cement on every seam. Works great and never have problems.
     
  8. trailblazr81

    trailblazr81 1/2 ton status

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    Is it leaking from the head area or collector/exhaust pipe area? If by the heads, I ended up having to double the gasket on one side. The only thing I could do to stop leaking was using 2 thick Mr. Gasket header gaskets. High temp and Copper would still leak. Also you must constantly check and tighten the bolts on headers. If you use a gasket sealer use the copper stuff. Tighten the bolts, let the engine get warm and cool then retighten your bolts.
     
  9. beater_k20

    beater_k20 Banned

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    ditch the silicone, cut the flanges on either side of the 2 center ports, and you shouldnt have a problem.

    O cut here O O cut here O

    also, what are you using for bolts?
     
  10. FRIZZLEFRY

    FRIZZLEFRY 1/2 ton status

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    My ramhorn manifolds were cracked so I picked up some used regular ones and some new gaskets.

    That was in 93 and I have not touched them since :D

    I think the longest lasting fix is manifolds :p:
     
  11. Thunder

    Thunder 3/4 ton status

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    What BeaterK20 said has always worked for me with headers and SBC. And other engines for that matter. and Felpro gaskets.
     
  12. pvfjr

    pvfjr 1/2 ton status

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    Stick a hose in your ear and start pointing it at crap. :dunno: Kind of stethoscopic in a way...
     
  13. ecameron87

    ecameron87 1/2 ton status

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    I am using bolts with 7/16th head and an allen wrench hole in the head as well. I will go ahead and try to cut the flange and use manifold gaskets with no silicone. Thanks for the help.
     
  14. theperfectgarage

    theperfectgarage 1/2 ton status

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    And if your still having probs, PM me and your welcome to swing by my place off Rita Rd. And I'll give you a hand ( or at least a beer )
     
  15. mciahpv

    mciahpv Registered Member

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    Is 'stethoscopic' really a word?
     
  16. pvfjr

    pvfjr 1/2 ton status

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    Yes it is.:D Though I may or may not have known it at the time...:whistle:
     
  17. jeeptuff

    jeeptuff 1/2 ton status

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    Over torqued?? All you need is 15-20 Ft. LBS..
     
  18. francis

    francis Registered Member

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    hey man sorry to hear your having problems. my boss has a 4 wheel drive 79 dodge truck with a 440 and he had this same problem. after many gaskets, tubes of hi temp he found out that whenever he really stomped on it the motor toqured so much that one header would hit the frame!! so he put a chain on the motor mount and new gaskets and he fixed it!! also to tell where a leak is coming from look in the general area the leak is coming from and look for carbon build up. a leak that has been there for any amount of time will leave quite a mark. also if you don't see any black run your hand over the exaust about an inch away with the engine running and when you hit the leak you will feel air blowing on your hand be carful don't burn yourself. its best to do this on a cold engine. good luck let us know what fixes it!
     
  19. YELL78

    YELL78 Registered Member

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    dude make sure after you change the gaskets that you warm the motor and then re torque the bolts thats what i have done with all my stufff and i also use MR. gasket ultraseal gaskets i never have leaks oh yea i have hooker headers also.
     

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