Mazda 626 caliper in the front keeps locking

What was fixed? The two most common causes of locking brakes is a constricted rubber flex hose and brake fluid contaminated with a petroleum product. A constricted hose will only affect that one wheel. Fluid contamination will affect all wheels. To determine the cause you have to get them to lock up again, then loosen the steel lines at the master cylinder, and / or open the calipers' bleeder screws to see where the brake fluid is being trapped.