72 dart disk brakes

I am doing a disk brake swap, all the parts came from a 73 duster,upper a arm,spindles,rebuilt the calipers,installed a rebuilt MC,new hoses, new lines bleed the system with a power bleeder and the old fashion way. no peddle if i pump the peddle i get just a little but goes away fast. o ya i did install a port valve for the rear brakes. is the rod the wrong lenght?,bad MC need help thanks