Brakes sticking

The brakes on this vehicle have given me trouble since the day I bought it. It had been wrecked and I put it together from several others. I have replaced the calipers and flex lines. Still sticking. I then took it to a local shop. They said the rear brakes need to have hubs turned and adjusted, which they did, and did not even look at the front. So a day later I drove it and the front brakes are still staying applied. The caliper gets very hot. I am a parts changer not a diagnostic person and I need help in diagnosing this problem.

Thanks for any help you can give.