I have a 2001 4x4 ranger that seems to locke the front brakes when it is damp or when first driven in the moning.They do not stay locked but release when the peddle is released they just squeal the front tires until you drive it awhile.
My 96 Jeep Cherokee front brake locked up twice in the 10 years I owned it. My mechanic was able to fix the problem for relativly cheap. I think both times I was charged just over $100. I cannot remember what was causing the brakes to do this. I would have a mechanic look at your Ranger before any harm is caused to an expesive part.
The brake pad friction material absorbs moisture as the vehicle sits. Then when the vehicle is driven this moisture causes the brake pads to grab causing the brakes to lock up. Once the brake pads get hot enough it drives the moisture out of the pads and they no longer lock up.
The only fix I know of to fix this problem is to replace the brake pads.