Why are '98 Jeep GC brakes creaking?

When I am at a stop and I ease off the brake or ease on the brake to come to a stop, I hear a loud creak. Its not like a squeak or screech, it sounds like a creak. Once I let go of the brake it doesnt happen and it only happens when coming to or coming out of a stop. Everything functionally works fine, it just sounds kinda bad. Any ideas?