Used a new penetrating oil on a seized caliper bolt, and it actually made things worse.

Had a 2012 F-150 in the bay with a rear caliper bolt totally frozen. Grabbed this new 'fast-acting' penetrating oil a supplier gave me, sprayed it on, let it sit for 15 minutes. When I went to turn it, the bolt head just sheared right off, clean. Now I'm drilling it out. I think the stuff was so aggressive it weakened the metal. Anyone run into a lube that's too good for its own job?

3 comments

3 Comments

king.val1mo ago

Honestly, what brand was that stuff? I've seen cheap oils do nothing but never one that actively breaks things. Did it feel like it changed the texture of the metal at all, like made it sort of chalky or brittle before it snapped?

the_sam1mo ago

Check if the metal felt weird before it broke. Cheap oils can leave a gritty residue that weakens things over time. Did you notice any odd texture changes or just a clean snap?

hollywhite1mo ago

Used to think cheap oil was just less slick, not actually harmful. Then I had a bolt feel almost sandy after a few months with a discount brand, and it sheared right off under normal torque. Totally changed my view on how much the wrong lubricant can mess with metal on a basic level. Now I'm paranoid about any weird texture change.