Tackling rusty bolts on 2-1/Cat/Muffler

[proporsche]

Originally Posted by porschedude996

May be more effective if you could remove the whole assembly and work on it on a bench.

I can imagine the nuts on the heads how they look like when you see these.That would a big nightmare to try to lose those-mucho problema...

I`d for with little torch and grinder ,once you have the one side off use puncher and it will come off

Ivan

[Matthew_VA]

I just recently swapped out the hardware on my '84 exhaust. here what I used for anyone interested:

Went with M8-1.25 x 40 mm. Class 10.9 Zinc Yellow Hex Head Cap Screw bolts - Amazon ID (ASIN): B007IAEDIA

M8 x 16mm Flat Washer High Strength HV200 DIN 125A Yellow Zinc Cr+6 washers: ASIN: B0CVD5HHQW

Self Locking Copper Nut: https://www.pelicanparts.com/More_Info/0009903250.htm?pn=000-990-32-50-M36&bc=c&SVSVSI=0580

Could also use these: https://www.ipdusa.com/products/11455/Copper-Flanged-Lock-Nut-CRP-11621711954-Volvo-946036-948645?srsltid=AfmBOopg8gahyW8rR5wwMCJ17gsb_Cl9v1Q XSCVtZCn-0Cl1CNjvX1aq

[r55forme]

Thanks Matt for posting the hardware too. The links didn't work for me but I'll search for them on Amazon. I will definitely need a lot of those.

Yeah my exhaust manifold bolts are equally bad if not worse. I would have to drop the engine entirely to have enough room to work on all that. I'll try some heat, I have an air chisel where I may just have to try and slice through the nuts and drive them off. I got distracted trying to fix my door panel and waiting for the inductive heater to arrive from Amazon.

I also appreciate the advice of not burning the house down, I'm definitely a fan of avoiding fire.

I'll take some pictures as I go and probably come back to seek solace and deep breaths when I get frustrated

[Matthew_VA]

thanks for letting me know, replaced broken link with Amazon ID so can just search off that.

Originally Posted by r55forme

Thanks Matt for posting the hardware too. The links didn't work for me but I'll search for them on Amazon. I will definitely need a lot of those.

Yeah my exhaust manifold bolts are equally bad if not worse. I would have to drop the engine entirely to have enough room to work on all that. I'll try some heat, I have an air chisel where I may just have to try and slice through the nuts and drive them off. I got distracted trying to fix my door panel and waiting for the inductive heater to arrive from Amazon.

I also appreciate the advice of not burning the house down, I'm definitely a fan of avoiding fire.

I'll take some pictures as I go and probably come back to seek solace and deep breaths when I get frustrated

[r55forme]

Just posting back--thanks to everyone for all the suggestions. Here's what ended up working for me in order of increasing desperation. I ended up using all the tools and learned a few new tricks using the air chisel.

One method I found helpful was to use a sharp chisel to cut a slot in the rusted nut, then shift to the angle to drive the nut counterclockwise. I didn't have to split the nuts, but the slot was enough to quickly get many of the nuts to rotate. This was much faster than trying to cut off nuts that wouldn't yield to the heat and nut extractors.

1. PB Blaster on all nuts
2. Nut extractor kits (simliar to this https://www.amazon.com/dp/B0CKQKFLJL)
3. Inductive Heater (https://www.amazon.com/dp/B0DK8F3GZ8) -- this definitely helped
4. Dremel Cut off wheels (https://www.amazon.com/Dremel-EZ456B-2-Inch-Rotary-Cut-Off/dp/B000FBLRVU/) only thing I could fit in there
5. 7" long Pneumatic Chisel and Punch (drive stuff through/apart)
6. Hammer/Punch and 18" long socket handle and various extensions

New exhaust is on and working great. I ended up filing out the rusty insides, grinding the mounting surfaces flat and smooth, and using stainless hardware and nickel anti-seize in the hopes that I will never get to experience this joy again.

Here's a few photos.







Again, thanks for the all the tips, it took some time but worked out well in the end.