shane_park92•1mo agoMost Upvoted

Found an old timer's trick for seized exhaust bolts yesterday

I was working on a 2002 F-150 in my shop near Dallas, rusted exhaust manifold bolts were giving me hell. An old mechanic walked by and said to heat the bolt red hot, then tap it with a hammer before trying to turn it. I tried it and it worked on 3 out of 4 bolts, only snapped one. Got any other tricks for rusted bolts that actually work?

3 comments

3 Comments

nguyen.angela1mo ago

Yeah but that tapping trick is the whole game right there, you gotta shock the rust loose before you even think about turning. I've had bolts that looked totally fused just pop right out after a few good whacks with a hammer. Heat alone can work but it's way better when you combine it with that vibration to break up the corrosion. That's probably why you snapped one too, you might've skipped the tapping on that last bolt.

aaronsullivan1mo ago

Tapping it before turning is the real secret, most people skip that step and just reef on it. I've had good luck with PB Blaster and letting it soak overnight, but nothing beats heat for the really stuck ones. Kano Aerokroil is pricey but it's the only penetrating oil I've seen actually crawl into threads, it's way better than WD-40. Do you ever use a torch on aluminum parts or do you have a different trick for those?

ivan7741mo ago

@aaronsullivan Yeah, aluminum's tricky with a torch. You gotta be real careful, I usually just heat the steel bolt and let it transfer instead of hitting the aluminum directly. PB Blaster's good but Kroil really does creep somehow, almost like magic.