My '67 was pulling to the right upon braking so I decided to bleed system. Successfully bled three brakes with a vacuum gun until front drivers side caliper: nothing came out . Removed bleed valve and tried to suction directly from caliper--still nothing--and brake pedal pressure remained firm with bleed valve still removed. Also note that stepping on brake forced no fluid out of caliper. I assume that means there's total blockage in the line to that wheel (which would explain the pulling)--other side bled fine. What should I do next? Please explain in detail as I will attempt to perform any viable solution. Thanks greatly.