driving home from work, i exit the highway onto the frontage road. i can hear a rough, rattling noise like a worn out pullythen i apply normal pressure to the pedal and i feel kickback for a few seconds then it goes back to normal. i am stumped on this one, i checked fluid levels, all good. belt good, hoses good. there is rust around where the brake reservoir goes into the part on the firewall, a leak at one time but nothing now.

 

maybe some of the rear drum hardware has come loose and is banging around inside the drum..