2001 lincoln ls v6 left rear is squeakin when i

How are the rear brake rotors and calipers. If you do not take them apart twice a year and clean up rust, lube certain parts, the pads will drag. Also if your caliper is from 2001 it may be all rust inside,especially if you do not change/flushing your brake fluid every two years. I also have a 2004 LS and 45 years experience with this and never a problem with brakes on any veh from 1962 thru 2009. It is all about neglect and lack of knowledge ,not to be hurtfull here.