Can This Be Right???

[NJFJ40]

This pic is where the exhaust pipe flange mounts to the manifold on my 02/80 FJ40 (stock manifold = no headers). The donut gasket goes in between and is recessed into the manifold lip. The problem is the ex pipe flange does not competely cover the hole in the manifold - you can see the edge of the new donut gasket through the crack.

I can't imagine this is as it is supposed to be. But the ex pipe flange I removed lines up with the studs on the manifold and has the converter for two pipes which mounts correctly to my exhaust system (via another gasket).

Thoughts would be welcome. I don't want to put this back on until I can figure this out.

Regards,

AndrewT

 

[NJFJ40]

Bump - And I added another picture in case the first one was confusing.

Come on - someone here surely knows this. Is it normal to be able to see the donut gasket between where the exhaust pipe flange mounts to the manifold??

 

[folsom50]

NJFJ, yes it can be normal. At least with all the trucks I use at work. I would have replied yesterday, but the gasket you use on your '80 is different than what I have on my '78.

 

[65swb45]

Last time I changed one, it snugged up flat. Not visible.

 

[Blue60]

Just did the complete exhaust system on my 2/79 over the past couple weeks. My donut gasket is not visible, and my exhaust flange "bottomed out" against the manifold all around. I was concerned that I hadn't contacted/"crushed" the donut gasket, so I pulled it off to check... had indeed slightly crushed the donut gasket therefore hopefully good seal.

The only thing that comes to mind is whether or not your flange and matching surfaces are indeed flat and otherwise not distorted?

Good luck, let us all know what you find out!

Cheers, and Keep on Cruising!

Dave

 

[NJFJ40]

Thx for the replies.

In the pix, the flange is just resting on the manifold (its not bolted down) and will compress the donut gasket as I bolt it down. Also, the flange surface is smooth and will bottom out nicely on the mating manifold surface.

The issue I see is that the flange edge is basically right on the edge of where the donut gasket is. I just don't understand why they designed it this way. If the flange was just a little bigger, there would be no issue. I guess it doesn't matter as a metal to metal seal would not keep exhaust from leaking so the donut gasket is doing the heavy work here in terms of preventing exhaust leak at this joint.

I plan to bolt it down tonight and install.

Thx Again,

AndrewT