Hey guy I'm having some problem with my 99 wj 4.7L i just put in a rebuilt 4.7L after sitting for almost a year and a half. after driving it for the first time i noticed my brakes were not releasing so i replace the caliper and had the rotor turned bleed the whole system twice and i still can't get it them to release all the way i hear the brakes rubbing when I'm driving.

My thought were the it could be the master cylinder or the Proportioning valve but I'm not a 100% on either. Any thoughts?