Replacing exhaust flanges

I have a leak on the passenger side exhaust, downstream of the second Cat on that side. I have replaced the gasket and wire brushed the pipe. It still leaks. I think it is because the flange has rusted and the thinkmes isn't there any more. I have tried non-OEM gaskets too, same issue.

I am leaning towards cutting out the existing flange and welding in a new one. The Cat is fine so I don't want to replace the entire assembly.

Anyone have any experience welding in new flanges?

View looking up



View looking down from top. Not a lot of flange left on one side.

 

That gasket doesn't look right

 

Ive done it, not difficult but you need a welder or a friend who can weld.

https://www.oreillyauto.com/detail/...ca2e3/nickson-exhaust-flange/nic0/31871?pos=0
You could try this, I’ve never tried them.

Or bring it to any muffler shop.

 

Flange is bent, wrong gasket, should have the spring bolts on that joint.

 

I highlighted the joint that is leaking with a red rectangle below. The joint with the springs is the next joint down stream. The gasket I purchased was part number 90917-06083 which I beleive is the correct part number for that joint. Flange on the cat side of the joint has rusted a lot and is much thinner than it was originally.

 

Before cutting....

Like others have said...you need to ensure you two flanges are flat. Use a flat block a wood with coarse sandpaper stuck to it and go over each flange until you have clean metal all the way across. Then hit it with Scotch pad to smooth it out. Use the correct gasket and use some Walker Exhaust Sealing Compound (also called acousti/seal)...stuff works great on exhaust systems. Really helps to fill in any pits/crevices/etc.

 

BTW as for a sanding block I cut a piece 3/4" (or 1/2") thick plywood into a 12"x4.5" block and use a roll of sticky sandpaper like this. Handy for all sorts of sanding jobs where you need a flat, shiny surface. I have 4.5" blocks of various lengths for different job.

 

I welded mine all the way around. Looks terrible but it’s quiet again. Bought some time.

 

Make sure it is installed properly.

An exhaust shop (if the metal is good) or used is cheaper than new.

 

Probably not ideal, but some of this might work: https://www.permatex.com/products/oreilly/permatex-ultra-blue-rtv-3-5oz/

I'm about to tackle the 3 cat gaskets on my taco as soon as I get the parts. Hopefully this week.

 

I just did the same thing using this gasket from NAPA https://www.napaonline.com/en/p/EXH31332

worked fine, and my flanges look worse than yours.

EDIT: disregard. I did the one on the upper end of the cat, so different part number.

 

I've used that stuff before. It doesn't work great. Your flanges would have to be almost mirror smooth and mated to each other for it to work.

 

Gotcha on the spring bolts, the gasket I got was like a steel wool circle that kinda squished between the flanges.

 

Could also chop the flanges and use an SS band style clamp if all else fails..example below, I don't know the proper size for it, but you get the idea.

https://www.summitracing.com/parts/sum-683250?rrec=true

 

I'm going to cut off the flange and weld in a new one(s). I've got some other exhaust work planned (needs a new muffler and the exhaust manifold is leaking) so when I do that work, I'll address the flanges.

I found this video of a guy welding new flanges on his Tundra. Looks pretty straight forward.

https://youtu.be/Rc8EzGsBAAQ?si=CCsT6A8EocAgITPP