do i need to change the brakes?

You are right, the brake has stuck on for some reason - either due to the handbrake cable not releasing or maybe the lining has become detached from a brake shoe. Its easy enough to check - prise off the central grease cap, remove the split pin from the castle nut if there is one, and pull the brake drum clear. The shoes can then be seen and you should be able to ascertain the damage. Its likely that the shoes are ruined if the brake has been stuck on for some time, so budget for new ones - considering that the opposite side should be done too to get ideal brake balance. Its also a good time to free off and lubricate the adjusters when you are in there.

John
June 2009