why would my front brakes lock up while driving. on 1992 Lincoln Town Car

I was driving on the road and the front brakes locked shut and the brakes became vary hot. I stop when the floor board became warm and I drive to a gas station and he bled off the front brakes and I was able to make it home. I had the brake rotors and pads replaced about 3 weeks befor.

Why would the front brakes lock up while driving? I was told by a friend that the brake fluid lines may be cloged and that they have a line within a line. One to the brake and one to return the fluid. Is this true and what would the cost be to replace the lines?

Asked by for the 1992 Lincoln Town Car
My town car will be ticketed for non op on street, if I can't solve this brake locking problem soon. Now the battery is dead; been sitting since May,2010
2 more answers , 2 more comments
the brakes lock because you need a new rubber brake line because it collaspes at times, believe me even if it do not leak it need replacing
I replaced both front lines on my 1991 lincoln towncar. I am working on my brakes now and replaced replaced the calipers, rotors, pads, and lines and the brakes still lock up. It is the Master Cylinder or the Brake Pressure Control (Differential) Valve.
And you do the same with your wife