kal

Getting through a military background check is usually no big deal. A defaulted loan isn't going to be a deal breaker. They will run a credit history along with a criminal background check on you. If you normally pay your bills on time, this will be a non-issue. Be honest when filling out your paperwork. Like someone said, they aren't loaning you money, they are looking for patterns of reliability and if you are a prime candidate for bribery.

They have backlogs of investigations. Your investigation will probably be completed somewhere in your training. If you are honest with them about your past (within reason, admitting to being a serial killer will probably be a rejected clearance), you will be OK. If they uncover untruthfullness, then it will be a difficult process.

Again, this usually isn't a big deal. It isn't some big hurdle that will get you dq'd.