Question to all the welders out there!!!

This question should be posted in the related forum, but welcome to the forum! You are in a wealth of knowledge around here.

If I were in header leak city, the first place I'd visit is a tight fitting tube area. Check your tubes and make sure none of them are contacting the block or any other components, or binding with the exhaust system. Disconnect them from the exhaust bolt flanges to do the gaskets.

If they are not sealing on the copper gaskets, pull them off and examine the carbon pattern on the flange, to determine where they are leaking. That can tell you if one area or a lot of areas are the problem. If it is more than one area, it might be tubing interference. If it's isolated, you could have a slightly warped flange that could be filed straight.

Depending on the quality of header, and the thickness of the flange..

I've lost count,, but dozens of times I've had to Flat file the flange true,, sometimes welding up a low area.. Check the flange sealing surface (welds) with a straight edge..

Other times the flange is warped by over-tightening, particularly the middle two..

This applies to new as well as used headers.

I always check em before I install them..

hope it helps..

Try double gaskets on each side.old or used headers or ones with flanges cut.flaten header flange surface with large bastard file,knock off any high spots on the welds.had a new set of hooker pro comps.the black ones with welded on badges wouldn't seal had the put em on a big surface sander used to retrue heads.ended up useing copper o-ringed gaskets from Ed hamburg.

If possible use a COPPER backing plate to the back of the weld. This will make the welding a lot easier. The copper will not stick to the weld bead.

Good call. I do this on some of my stuff, as well. It acts as a heat sink. Keeps warping down. A copper heat sink on an outside corner joint or a butted edge, on both pieces, as near to the weld area as you can manage, will keep the edge from burning away/ heat soaking to melt the edge of the metal away and allows the weld to bridge.