exhaust gasket sealant?

[MAKG]

I broke off the cat/Y-pipe bolts like I described on a (then) stock-height 1986 Bronco II, and on my current 1991 Exploder. It didn't take much.

 

[Yellowsplash]

Must be nice having that 3 foot cheater, haha. His problem is that there is no nut or bolt heads left to get a socket on. Theyre rusted out..

 

[Sevensecondsuv]

MAKG is giving away his California location.

He mentioned something about putting a wrench and/or breaker bar on the bolt. I guess he's never seen an exhaust flange that has little shapeless mounds of rust where the bolt head and nut used to be...

I just ended up cutting the bolts inbetween flanges with a sawzall. This damaged the flange faces but I welded them up and then ground them flat. It sealed just fine with a new gasket plus muffler mend. I would also definately use SS bolts and plenty of antiseeze when putting it back together. Then maybe you can use MAKG's method the next time you take it apart.

 

[CraigK]

Okaaaay . . .

Got the %$#*!%$# bolts off. (But I'll need physical therapy now.) Flanges on the cat have been hammered ~flat and held up to a belt sander to resurface - look good. But the Y-pipe flange and muffler flanges are still a bit iffy, and I can't get them into the shop to do a better job.

Question: Is this Muffler Mend, if used with a gasket, hard to get off? As in scraping off a flange to redo the gasket if it begins to leak again a year from now? I think I'd rather have a plain gasket that I can easily scrape off and remove to replace, should it be necessary, than use a cement that I will unable to remove to properly prepare the surface again.

Thoughts? Experiences?

CraigK
P.S. - the "bolts" and "nuts" were misshapen blobs of rust with NO possibility of accepting a socket/wrench. And I had already tried a makeshift sawzall to get the bolts off. I shaped the end of a hack saw blade so it would insert into my jig-saw, and tried cutting through the gasket that way. No go, and more physical therapy.

 

[Yellowsplash]

CraigK, Ive never personally used the muffler mend, but I dont believe it is a cement type substance, but more of an rtv silicone type. Hopefully someone else can confirm this.

 

[AllanD]

On EVERY V6 EFI ranger cat flange I've ever seen the studs are serrated shank press fit in the cat flange.

these studs take nuts on the Y-pipe side.

there is nothing to put a backup wrench on.

I usually torch them off, grind them smooth.
Heat with a torch until light Orange then knock them out of the cat flange with a tapered punch on an air chisel.

THEN replace them with stainless steel bolts.

Though on my personal truck I used Monel bolts and oversized
stainless steel nuts.

the problem Kunar is having is a common one and it has little or nothing to do with the bolts (except inhibiting his ability to fix it)

The flange rusts away until the relatively narrow sealing surface at the top left of the gasket as pictured leaks.

My fix for that is an '88-94 cat and Y-pipe.
Those use an oval pipe and a similar mating flange
bu there's a "pilot tube" that extends into the front cat chamber
and acts as a baffle to protect the gasket from direct exhaust pressure.


what is required to seal the '86-87 two pipe flange is to weld it up
and grind it down.

AD

 

[Sasquatch_Ryda]

Get yourself some Permatex Ultra Copper II sealant, thats what i've been using for cat flange gaskets for a long time. I've never had it blow out yet. I'm just using that on my ranger without a gasket and its been fine for over 3 years. I've used it on manifold to y pipe connections as well and never had any problems.

 

[CraigK]

Job is done. I could not find anyone locally, or on the internet, that sold "Muffler Mend". I used gaskets and the Hi-Temp Ultra Copper Permatex RTV Silicone, with all new 5/16" SS bolts and nuts, with LOTS of anti-seize compound. It's been two days, and it seems to be holding with no leaks . . .

I'll install the new O2 sensor tomorrow.

Thanks for all the helpful replies.

CraigK