The front brakes keep locking up when driving

Welcome to 2CarPros.

You have replaced a lot. However, even if there is a slight drag on the brakes, the brake fluid will get hot and expand. Thus, it will eventually cause what you are experiencing.

By any chance, when the master cylinder was replaced was the push rod inspected for adjustment? Next, did anyone by chance replace a brake light switch? I've seen them installed incorrectly causing pressure to remain on the brakes.

If none of those help, tell me this. Are the brakes always locked or does it only happen after driving? If they are always locked up, we need to work backwards to identify the cause. I would start at the brake caliper and open the bleeder to see if that releases the caliper and the wheel turns freely. If it does, work back to the brake master cylinder and do the same to see if that releases the brakes. If it does, then the problem is between the brake pedal and the master cylinder.

Try that and let me know what you find. Also, let me know if you have questions and if this has ABS.

Take care,
Joe