Old timer at my last hangar swore by using brake cleaner on everything

Dale, this guy who's been turning wrenches since the 70s, told me to spray brake cleaner on a stubborn fuel fitting instead of wd-40. I figured why not, it's just a cleaning spray right? So I hit this frozen nut on a Cessna 172's fuel line, and the thing came loose in like 10 seconds flat. But then I saw the rubber o-ring underneath had turned into a gummy mess from the chemical eating it. Had to replace the whole fitting, cost me 45 bucks and an extra hour. Has anyone else had a go-to hack that actually ruined something instead of fixing it?

3 comments

3 Comments

ivan_mason1mo ago

Read somewhere that brake cleaner turns into a corrosive gas when it gets hot, so some old school guys use it on exhaust bolts too. That's a Sure way to wreck an O2 sensor if you aren't careful. Your story is a good reminder that what works for one part can destroy another real quick.

harper6931mo ago

You ever try PB Blaster on exhaust stuff? I swear by that stuff for rusty bolts, but you gotta be smart about where it goes. I was doing headers on my old Civic and sprayed it everywhere, then realized the O2 sensor was right there. I just pulled the sensor out first and taped off the bung. Saved myself a headache, but man it was a pain getting that sensor out with all the rust. Lesson learned, now I always unplug and remove anything sensitive before I start dousing stuff in penetrant.

felix_hayes641mo ago

Man I learned that lesson the hard way on a buddy's Subaru, soaked the downpipe bolts with brake cleaner and fried his rear O2 sensor instantly. It's wild how one little mistake can turn a 5 minute job into a whole afternoon of replacing parts.