Right front brake locks up

The most common suspect would be the rubber flex hose is coming apart inside and preventing the brake fluid from releasing. To verify this, stop on a slight incline, place a block about a foot down hill of one tire, shift to neutral, then open the hydraulic system at various places to see where the fluid is being trapped. When the hose is blocked, the only place you can open to make it release is the bleeder screw on that caliper.

If opening the bleeder screw doesn't do it, the next suspects are the caliper mounting bolts. The area shown must not have any rust spots or lifted chrome plating. That will prevent the caliper from sliding freely. That area also needs to be lubricated with special high-temperature brake grease.