Caliper Bolt is stuck halfway out
 

1997 Cavailer.
Trying to put brakes on it. The bottom bolt came out but the top bolt broke loose turned about 3 or 4 full turns and then jams. I am thinking of getting the 3/8" allen wrench socket for my impact wrench.
Should I?
Has anyone else seen this?

you should try using pb penitrate u can find it at walmart in the automotive section, spray it on and work the bolt back and bringing it out little at a time. if that dont work then use the ipact and i sugest after you get it out use a tap and die set to fix the threads