Ok, I taped the top bolt hole of my break caliper because the last person cross-threaded it ... I can't get a new bolt through the damaged area by hand, and I have ran that tap through front and back, blown out any shavings with air and used oil to lubricate in the hole like 100 times! The tap EASILY goes in and out by hand (just the tap, no handle needed) What am I missing?

Did you make absolutely sure that the tap had the exact same threads as the bolt and hole, was metric, etc?

Also make sure that the bolt isn't messed up, if the threads are pinched even a tiny bit it can make it had to get in by hand.