john689089

Started to change front pads and rotors on my GX470, but couldn't get the caliper bolts loose. Is it safe to use a torch to heat up the area around the bolts so I can loosen the bolts? Any other way to break these bolts free?

chiph9

Do you have an impact wrench?

Also - dumb question - you're sure you're loosening the bolt? (because the bolts are on the back, not the front, and face the "wrong" way)

Chip H.

john689089

No impact wrench. Yea, that's a pretty dumb question. Righty tighty, lefty loosey. I'm well aware which direction to loosen a bolt.

shyguyF

Turn the key at "on" position and turn the wheel to which direction that is easy to unbolt the bolt.

co4wheel

PB Blaster. Use it on every bolt on the suspension DAYS before you try and loosen it. Spray it on and let it sit overnight. Use only 1/2 inch impact tools on these type of bolts. Longer handle. Better contact with the head of the bolt. Use a short breaker bar as well if needed. Totally worth having a shorter breaker bar.

tz693

You can use torch to heat it up and soften it. I did that on my other car. For safety, get a fire distinguish handy. Good luck.

IanB2

I'd use heat on those bolts only as a last resort, too much rubber (brakes hoses, piston seals, etc) in the area that could get ruined. PB Blaster, tap it with a hammer, breaker bar. And I live where they heavily salt the roads, I know crusty bolts, lol.

angelslex

Use a longe pipe on your wrench or socket. Make sure is a MM.
Little heat won't hurt but make sure not to over do it.

BlackCat81

NEVER use heat on a bolt, heat expands and softens metal. It'll shear the head off before it comes out. Heat the surrounding area of the bolt to expand the metal off the bolt threads. Buncha noobs up in here.

Edit; and they're not frozen. Somebody probably impacted them on. Get a wrench, or a socket on it, and hit it with a hammer. Easy peasy. As a tech, I've done 36 trillion brake jobs and never had a seized bolt.

SkeetShoot

Also, Make sure you are using the correct METRIC socket. Don't use the fractional sockets. Especially when a bolt is hard to get off. That in combination with PB Blaster will work wonders.

co4wheel

Brakes and their components are designed for a LOT of heat. Enough heat that they can make the hub bearing grease fail before the brakes fail. A little heat on the hub or near the bolt won't hurt a thing.

john689089

Thanks to everyone who responded. Used PBlaster and let it soak overnight, then again this morning with a few hammer taps and managed to get the bolts out. Thanks co4wheel and IanB2 for the suggestion. Glad I didn't have to try the heat!

co4wheel

PB Blaster is the best. Glad it worked. I start with it a week before my projects. Just to be safe.