exhaust headers leaking

sportsfan · 09-09-2009, 06:22 PM

Hooker super comp headers on SBC ,can't get good seal against heads.Tried regular gaskets,now using copper .Bolts are always coming loose.Even with bolts tight center tubes still leak .Any suggestions?

FED 387 · 09-09-2009, 06:40 PM

are your header flanges absolutely flat??? Comp387

sportsfan · 09-09-2009, 06:52 PM

Not sure if they are flat.Had headers coated a few years ago ,can't remember if I had this problem before

njk53 · 09-09-2009, 07:13 PM

We have a BB Chevy and also use Hooker Super Comps. Hooker is known for ill fitting poor sealing headers. You have to remember they are mass produced so the attention to detail is lacking.

Take a straight edge and check the flange as suggested in the other post. If you have more than a few millimeters of daylight between the straight edge and the flange I would consider sending them back to Hooker. Also check for cracks in the welds/tube.

If they are an older set, what we do is we use the Fel-Pro high performance header gaskets. Make sure the gaskets are new. We also put an 1/8 in. bead of Permatex Ultra Copper silicone around the header tube/cylinder head interface on both sides of the gasket. Usually we stick the gasket to the cylinder head and then mount the header. You can also put a dab of silicone sealant on the header bolt to help keep them from loosening. Tighten them down snug but don't go overboard. Don't start the motor until the silicone is fully cured. Preferably overnight. The job can be a little messy but it all wipes off when the headers are tightened down. It works well for us. It is an economical fix and worth a try.

Bruce Schoenbaechler · 09-10-2009, 03:44 AM

If they are an older set and you can't send them back , and all else has failed, you can cut the flange between tubes and they will seal. I've had to do this quite a few times to get even some custom built headers to seal.

WALZEE · 09-10-2009, 10:30 AM

throw gaskets in trash, use only small amount of ultra black high heat silicon, bolts will not come loose, they will not leak, you can take all the bolts off and header will not fall off, you should never have an issue.

greg fulk · 09-10-2009, 05:37 PM

I'll tell ya what.... on a SBC the ONLY thing we'll use is the STOCK manifold steel gaskets! steel side out! They work you can't tell me any different the engine in dad's old Camaro had 8 seasons on it & never leaked! this is what all my buddys use on their street cars with no trouble!

09-09-2009, 06:22 PM	#1
sportsfan Junior Member Join Date: Aug 2004 Location: Somerville,New Jersey Posts: 34 Likes: 0 Liked 0 Times in 0 Posts	exhaust headers leaking Hooker super comp headers on SBC ,can't get good seal against heads.Tried regular gaskets,now using copper .Bolts are always coming loose.Even with bolts tight center tubes still leak .Any suggestions?

09-09-2009, 06:40 PM	#2
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,416 Likes: 521 Liked 330 Times in 178 Posts	Re: exhaust headers leaking are your header flanges absolutely flat??? Comp387

09-09-2009, 06:52 PM	#3
sportsfan Junior Member Join Date: Aug 2004 Location: Somerville,New Jersey Posts: 34 Likes: 0 Liked 0 Times in 0 Posts	Re: exhaust headers leaking Not sure if they are flat.Had headers coated a few years ago ,can't remember if I had this problem before

09-09-2009, 07:13 PM	#4
njk53 Senior Member Join Date: Jul 2007 Location: East China, MI Posts: 504 Likes: 0 Liked 0 Times in 0 Posts	Re: exhaust headers leaking We have a BB Chevy and also use Hooker Super Comps. Hooker is known for ill fitting poor sealing headers. You have to remember they are mass produced so the attention to detail is lacking. Take a straight edge and check the flange as suggested in the other post. If you have more than a few millimeters of daylight between the straight edge and the flange I would consider sending them back to Hooker. Also check for cracks in the welds/tube. If they are an older set, what we do is we use the Fel-Pro high performance header gaskets. Make sure the gaskets are new. We also put an 1/8 in. bead of Permatex Ultra Copper silicone around the header tube/cylinder head interface on both sides of the gasket. Usually we stick the gasket to the cylinder head and then mount the header. You can also put a dab of silicone sealant on the header bolt to help keep them from loosening. Tighten them down snug but don't go overboard. Don't start the motor until the silicone is fully cured. Preferably overnight. The job can be a little messy but it all wipes off when the headers are tightened down. It works well for us. It is an economical fix and worth a try. __________________ Nelson Kowal Stock 345

09-10-2009, 03:44 AM	#5
Bruce Schoenbaechler Junior Member Join Date: Dec 2003 Location: Myrtle Beach, S.C. Posts: 33 Likes: 0 Liked 0 Times in 0 Posts	Re: exhaust headers leaking If they are an older set and you can't send them back , and all else has failed, you can cut the flange between tubes and they will seal. I've had to do this quite a few times to get even some custom built headers to seal. __________________ SCHOENY

09-10-2009, 10:30 AM	#6
WALZEE Junior Member Join Date: Aug 2009 Posts: 13 Likes: 0 Liked 0 Times in 0 Posts	Re: exhaust headers leaking throw gaskets in trash, use only small amount of ultra black high heat silicon, bolts will not come loose, they will not leak, you can take all the bolts off and header will not fall off, you should never have an issue.

09-10-2009, 05:37 PM	#7
greg fulk VIP Member Join Date: Jan 2003 Location: jackson Posts: 1,165 Likes: 0 Liked 5 Times in 3 Posts	Re: exhaust headers leaking I'll tell ya what.... on a SBC the ONLY thing we'll use is the STOCK manifold steel gaskets! steel side out! They work you can't tell me any different the engine in dad's old Camaro had 8 seasons on it & never leaked! this is what all my buddys use on their street cars with no trouble! __________________ Greg Fulk 308 308X P/SA "ALL AMERICAN"