Rear Brake Issue?
 

Ok to start off, the truck is a 2003 F350 DRW 6.0L 4X4. So i knew i needed to do rear brakes but i had time. on friday coming down a decent hill, i started to brake and the whole ass end of the truck started to hop. i was concerned pulled off to investigate and saw and smelled nothing so i figured since it was hot out and the road was just paved that it had some ripples in it. Then sunday i heard a grinding noise. Monday i ripped the calipers off to see what was going on and my drivers side outer pad had 1/4 left, inside was metal to metal and the inner rotor was scuffed but not terrible. passenger side inner and outer both had 1/4 left on them. Since no one had rotors for my truck i got a cheap set of pads to throw on to get by for now. My question is now driving it for 2 days, it stops good but every once and awhile it feels like something is shifting in the ass end. Maybe its just me but it dont feel right. Caliper bolts are tight. Only difference i made were new pads and i had 60 psi in rear tires and i bumped them up to 70 psi..... i was thinking of dropping it back down to 60 psi. Also when backing into my driveway real slow, when i hit the brakes not too hard but not to soft either, the ass end of the truck bounced up and down one time. I maybe just paranoid that with running the pad metal to metal that it aint the same like it was if that makes any sense?

It can be a combination of several things but my 1st is the tire psi- drop it down and second, the brunishing of the brakes...whether they are high or low end linings, given the variable damage (wear) to the rotors, the bedding of the pads will vary based upon type and amount of surface contact- which changes the amount of "bite', so i would say that what you are experiencing is not unexpected. Once the rotors are turned/replaced and new pads installed everything should be fine.