Exhaust bolts


#1

i removed downpipe from exhaust manifold and all 3 nuts came off studs easily. they were almost finger tight. but they look very corroded. i assume they are at least higher quality nuts since they see high heat and luckily did not seize. they are very hard to reach. but i got them off. should i replace them? where do you find high quality hardware? dealer?


#2

The dealership would have it, yes. I usually replace them no matter how easily they came off - gives me that many fewer years of corrosion, which will seize them eventually.


#3

Let’s not go under the assumption they are "high quality " nuts. I’ll bet many a more corrosion resistant nut will work. But, woe is you. You still should match the metals for compatibility so yes, go to a dealer…coming and going, sigh. Expect to pay the high quality price though.


#4

+1 to @shadowfax Wire brush the studs as well before re-installing to clean up the threads, too.


#5

Haha. Wirebrush? I used 18" extension to reach nuts


#6

Year, make, model ??? Good luck trying to obtain nuts and bolts from the dealer…During the life of this vehicle, how many more times will you perform this job? If the old parts are serviceable, use them!


#7

I always replace nuts and bolts when doing exhaust work, usually with stainless steel and usually with a dab of antiseize. In addition to preventing seizure, antiseize also tends to inhibit electrolytic corrosion.


#8

It’s been my experience that exhaust fasteners are often the easiest ones to remove until they become overly corroded. I think the frequent temperature cycling keeps them from freezing in place compared to one attached to the frame for example…That’s probably why they were relatively loose. if it’s just surface rust, I would just lube them up with anti-seize and run them back on. Loss of material from rusting, replace…


#9

wirebrush the studs: Use a battery terminal cleaning tool. Butcher it to an extension if needed. They come in smaller sizes, but you might need to look around. You can also get brushes that will work made for other tasks, as well, but new battery terminal brushes work well even for 3/8" (10mm) studs. Little more work than a smaller one made for the stud, since they may not grab tightly.