Hey, a month ago my brake pedal started to shake when i push it. So i was thinking maybe my disc are warp in the front but i dont think they are because the steering doesnt shake when i brake. A week ago i was ajusting my rear drum and i see when i turn the wheel freely, the wheel stop for no reason. Like if the drum wasnt a perfect circle. I dont know why this happen because my both rear drum are brand new from this summer. Maybe i should get them turn?

Disc / brake warping is a myth. (just letting you know, not bashing on you)
http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

Have your drums turned, should help. Drums are not a percect circle, there will be slight low and high spots from braking, and pulling the parking brake.