1983 Dodge Van Dodge B250 Van Brake Problem

I recently had some front brake work done, which included new pads, new brake hoses on both sides and a caliper on front right. Shortly after these repairs I noticed that my front brakes started to lock up intermidently when I braked medium to heavy stopping but not when I feathered the brake pedal. Now the front brakes have totally locked up and the only way to get them to release is to bleed them, I usually bleed the front left and it releases the brakes.

Any ideas of what might be wrong? Your input will be greatly apprecaited!