Raymond, don't spend the $12.00 for the brake experiment.

If you don't mind experimenting with old caliper brakes, I will give you a pair. I have a million of them looking for homes.

Just tell me what size bolt you need and I will them to you.

If there is one reason that caliper brakes might work it is that they are easier to center. I wonder if one of your pads is applying more pressure than the other resulting in squeeling and lack of proper brake power.