Here is an interesting question. I was going to replace my rotors this weekend but i could not get those two big bolts that hold the caliper in place. Not the caliper torx bolts. And man those Fcks are on there pretty dam tight too. I tried 18mm and 11/16 and neither one worked. They were close though so now, I have 2 rounded bolts to get off . But I digress. Does anyone know what size these friggin bolts are. Since it was assembled in Canada I thought it would be metric but I guess not.

 

Hmmm I used an 18mm 6sided socket and it worked fine. But now that its rounded Maybe its time for a pipe wrench and replacement.

99 F250SD EC 5.4L 3.73 285 BFG/ATs...
99 Expy EB 5.4L

 

Thanks for the input. Well I went out with a pair of vise grips and soaked them with PB Blaster for about 1 hour and low and behold they came off. I love my PB Blaster.

 

I had the same problem the first time I replaced the front pads/packed bearings, and decided to turn the rotors. I still have the 18mm socket that BROKE when I attempted to lossen the bolts. Manual says the factory torque is about 150 ft-lbs as I recall. No wonder. I'd say the best bet is a 1/2" drive impact wrench w/ 18mm socket (that's what I ended up using), or an impact socket with one long cheater bar.

Good Luck!