Originally Posted by
cxwrench
^All of this^. If you hadn't tried to take the brake apart all you would have had to do was make sure the nut on back was snug, center the caliper by hand, and then tighten the nut. Now you've got a little more work to do. The adjuster screw is probably ignored by 99.999% of people w/ tools.
I never regret taking a well used bike component apart. In addition to having a freshly cleaned, lubed and adjusted part, I usually learn something in the process.