You'll find it when you pull it apart. If it wasn't doing it before the shoes probably are not on backwards. A broken spring would cause the loud squeal but it usually doesn't cause it to pull to one side. They break after about 10-years of service, at least they did on the phone company vehicles. If you're doing a brake job buy new ones. Pulling or locking up the wheel is usually from the lining getting fluid on it. It's like a glass sitting on water on a table when you try to release it It wants to stick to the table. Even soaking them acetone is a temporary fix. That fluid gets deep into the lining and then the heat brings it to the surface again. Maybe you have a little fluid on them and without the spring to pull the shoes away from the drum they are sticking to it. The other thing is to jack of both front wheels and see if the brakes are locking up both sides. Maybe the wheel cylinder is frozen on the opposite side. Do not stretch those springs in place with a tool that will leave a mark on them, they will break on that spot. That is why you use brake spring plyers. Replace the springs on both wheels.
