Exhaust Flange Gasket

[JeepCJ5]

Hey guys, I have an exhaust leak between the exhaust manifold and the down pipe. What's the best way to approach this? I have a replacement gasket. I am worried about breaking off a nut or something. I am hoping to avoid having to take off the manifolds if I can! Any advice?

 

[mtnwhlr]

soak them good with something like liquid wrench for awhile before trying to remove them.

 

[Torxhead]

After soaking them, you can lock a couple of nuts together on each stud to unscrew them. I purchased a stud kit from the "Help" line of automotive products that included plated studs, extended length brass nuts, and lockwashers for replacement. Here are some tips if you break off the studs:Catalog

 

[mriplaybass]

As mtnwhlr said, soak them for a good long while with penetrating oil. When the bolts on my Explorer manifold were rusted tight, it took 2 days of repeatedly soaking, but they eventually let go. I like to use PB Blaster penetrating oil. It will not ignite the way all the others do if you have to heat the nuts or manifold with a torch to loosen the rusted parts.

 

[JeepCJ5]

Thanks guys, I'll go to town with PB Blaster. Thanks also for the link.

Justin

 

[Lumpy Grits]

Then use copper anti-seize on the reassembley.
LG

 

[JeepCJ5]

So after a couple of days with PB Blaster, I got the nuts off. I bought a gasket, but the slanted part of the exhaust manifold seems to be part of the manifold. I can't feel any seam inside. Is there supposed to be a gasket? I tried lightly taping on that part, but it doesn't move.

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[mtnwhlr]

In the first photo there is a black gasket, this needs to be removed by knocking it off you will then be able to attach your new donut. Does this make sense?

 

[Torxhead]

No, there is not a gasket. it just tightens up.

 

[JeepCJ5]

Thanks guys - looks like there is more than one correct answer! Maybe it is different by year or specific manifold? I'll try to tap it out again tomorrow and if that doesn't work, I'll just re-tighten it. I did notice that after loosening the firewall side nut, the loose flange part was already very loose, so I think maybe to front nut was not tightened up and that was where it was leaking.


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[Lumpy Grits]

No, there is not a gasket. it just tightens up.

Correct!
It's a crush fit between the header's 'dome' and downpipe flange. No gasket is used.
LG

 

[mriplaybass]

No, there is not a gasket. it just tightens up.

You can make sure by taking a magnet and putting it against the bevel on the manifold. It is probably magnetic, and part of the manifold. The type of manifold/pipe you show would not use a gasket. Take a wire brush, steel wool, sand paper, etc., and clean up the rust on the manifold and pipe and tighten things down.