Before yearly 1st time pull, I always remove each wheel hub, inspect and if needed, remove winter rest time rust using steel wool and brake cleaner fluid, replace worn out brake parts / wheel bearing parts, re-assembly and re-pack with fresh marine wheel bearing grease (that take natural moisture exposure). IMO, this "remove, clean and re-grease and adjust before one pulls" be mandatory for all trailers coming out of their winter storage months. If wondering, I do this task in storage yards as well - before towing trailer on the public roads. And, never had sticky brakes on any of my trailers.