Can we talk about using a heat gun on a seized caliper bolt?

Had a 2012 F-150 in the bay last week with a rear caliper that wouldn't budge. Tried the usual breaker bar and penetrating oil for 20 minutes, nothing. Grabbed my Milwaukee heat gun, hit the bracket around the bolt for about 90 seconds on high. Heard a loud pop, bolt came right out. Learned that sometimes you need to expand the housing, not just the bolt itself. Anyone have a different go-to method for this?

4 comments

4 Comments

the_felix3h ago

Man, I feel you on this one. Had a 2012 Silverado in my shop not too long ago and that same rear caliper bolt situation had me ready to kick something. Spent a good 25 minutes with the breaker bar and PB Blaster and it just laughed at me. Got the heat gun on it for maybe a minute and a half and it popped loose with a sound that scared the hell out of me. That expanding the housing trick is gold. I don't have the patience to sit there for an hour either, especially when the customer is breathing down my neck about getting their truck back.

skylerb532mo ago

Wait, you only gave it 20 minutes with the breaker bar and oil? That's wild, I'd be sitting there for an hour at least before I even thought about getting the heat gun out. I guess if it's a customer's car you gotta move fast, but man, I let that stuff soak forever.

grant4132mo ago

Yeah, I'm with @skylerb53 on the patience thing, but my attention span is about as strong as those factory threadlocker beads.

the_leo2mo ago

Hold on, 20 minutes? That's barely enough time for the oil to think about moving in. I'm with @skylerb53 on this, you gotta let it breathe. I've seen guys rush and snap a bolt clean off, then you're really in trouble. Giving it a proper soak is just basic sense, even if you're in a hurry. Rushing just turns a simple job into a huge headache.