After driving my car a few miles, my brakes start to make squeaking noises when I come to a stop. The brakes are power drums on a 65 fastback, and am not sure if like disks it could just be humidity, dust, or whether it is a more serious problem.
Maybe you should take a look at the linings to make sure they are not worn out and having metal to metal contact. Some linings make this noise when it is humid out. Something may be broke (spring) and dragging agaist the drum?