While I’m waiting for my Racing Beat muffler, I decided to paint my mid-pipe I noticed a small leak on the gasket. After I painted the pipe I sanded the flange and noticed a small indent in the flange, used some copper gasket spray and it don’t look like its fixed. Should I use another gasket or type of gasket paste?

 

There are high temp red and copper rtv's made by permetex you can pick up at any auto parts store Havent used any myself though so i wouldnt b able to tell you if theyre any good.

 

At work we use some thick black exhaust sealer, works great for exactly what you need it for. I'm not sure exactly who makes it, or if it will stand up to the extra heat from the rotary being that close to the engine, but I know it comes from napa in a white tube with blue and black lettering.

Your other option is to lay a straight edge across it and use an angle grinder with a sanding disc to take off the high spots. You might want to do this and use the sealer if the gap is big.

 

Ok, took the die grinder to it an picked up some Permatex muffler & tailpipe sealer that can with stand 1000+ degrees. Not the same but they didn't have one like you described.

 

Hey Chris - please let us know if the Fix does the job OK?
Stu Aull
80 GS
Alaska

 

i would have taken the pipes apart at the flanges and checked for warping of the flanges. i would then inspect and replace the gasket with a new oem mazda gasket. what yo're doing is just a bandaid.

 

It’s a new gasket from Racing Beat the min-presilencer only has 200mi on it, The flange is flush except for that what I took a picture of (it’s kind of beveled there) almost looks like it was meant to be there. Directly above that on the other side it a little pitted looks like rust was there but I cleaned it and have a good seal. Mazdadave anything else, do you think if I put a wield in there it might give me a fix. I'm kind of lost with this, the only option I thought of other then this is welding a new flange or replacing the pipe all together.

I'll keep you posted Stu, my muffler should be here today. After a nice drive I'll see if it fails.

 

my guess is that the flange on the midpipe has warped and the flange on the presilencer is good. i surface all of my flanges on a large belt sander a a freind's machine shop. with thisif you can get a hand sander with some coarse grit you may be able to flatten it back out. i would put a level or a straight edge on the muffler flange to confirm if it has warped slightly. welding will give you a fix but will be difficult to remove should you have to remove the mid pipe.

 

the bandaid did not even last 10mins by the time i backed it out of the garage the leak was back. I'll keep you posted.

 

every muffler shop ive ever been too has a BIG grinding wheel/belt sander, its job? to flatten flanges after weldong.

either sand it flat by hand the hard way, or bring it to a muffler shop, and give em moneys so they can buy the head of the neck

 

I called every exhaust shop in town and no one will touch it… Do you think a thicker gasket or two gaskets will work?

 

From the looks of it, the ears are bent out and probably rusted too. You could tap the ears in so it closes the center first. Use the gasket that has the crushable steel ring in the center. If that doesn't work, you may need to replace the flange.