Originally Posted by Big bird
i just went through this on a 74 GMC i own. it was a a blocked brake hose. the trash allowed the fluid to the caliper but would not return the fluid back to the master cylinder. that caused the calipers to lock shut!!!!
Good point. The way to check for internally collapsed flex line is to have some push and release the brake pedal, immediately crack open the bleeder screw. If fluid spurts out and the caliper releases the flex hose is the problem.
If you can't push the caliper back with the bleeder screw open, the caliper is seized.