Rear Wheel sound when rotating at Parking

[send2cooool]

Hi,
I have Corolla 2006 CE auto-transmission. I have been listening sound from rear wheel, especially when apply brakes since last one month. So, I went to mechanic and changed the rear brake shoes bcoz it was almost due, so mechanic changed the rear brake shoes and springs as well. While car at mechanic shop standing still, so I rotated rear right wheel, it is okay, then I rotated rear left wheel, it gives little sound as if something is striking inside the drum, so I asked mechanic and he listened to the sound and he said it is normal, I told him it is since one month, he said it is normal and did not suggest any solution. I feel that when I apply brakes something struck to drum and sounds, it is not like squeezing the brake shoes, the sound was there with old brake shoes and still with new brake shoes, so I feel it is not bcoz of brake shoes.
Any expert opinion would be highly appreciated.
Thanks.

[invader]

Remove drum and inspect...

[TrdSpeed140]

drum is rusty, a bit of rusty metal is probably just making contact with something when it spins. you should have just gone ahead and put new drums on while you were getting the shoes replaced. when I got new drums I taped off the contact surface area on the inside of the drum and sprayed a few coats of high-temp spraypaint on the drums to prevent rusting.

[invader]

Rust buildup on the drum's edge can touch the housing as it rotates. I knocked it all off with a wedge hammer.