73 duster front brakes locking up when coming to a stop.

Thanks for all the replies. When I can spend more time on the car I will try and get pics it is a factory 340 car..factory power disc brakes..not sure why the parts were missing from the rear...but they are there now...also it has a 81\4 rear end..may be it was changed....I thought it should have been an 8 3/4