Did the rear drums on my wifes 340 the other week as they were binding and have started again but have put this down to needing new rear handbrake cables. The end of the outer cable has a bit of rubber on it that fits through the small bracket and held in place with a slide clip which has seen better days and is trapping the cable enough not to release the handbrake fully so brakes are binding again which is a right P.I.T.A. because it's playing murder with the fuel economy.
Not to bad a job to do but just make sure you have copper grease to hand for the contacting faces of the shoes. And it makes it easier to remove the arms if you loosen the brake piston bolts a litlle.
morgan105