brake pedal chaders and rear drums get hot 1999 chevy

I have replaced the front pads and rear drums and shoes on my 1999 chevy 2500 van . When I press on the brake pedal to stop the van shakes and chadders and the pedal pulsates. the hotter they get the worse it is. Help! What should I do? Have you replaced the rotors or checked them for run-out?
Are the rear brakes shoes free of any contaminates like brake fluid or differential fluid?