Rinse all the canned beans under cold running water in a colander. Drain thoroughly and discard any discolored beans.

Chop the green pepper, celery, red onion, and pimentos into bite-sized pieces. Combine with the beans in a large bowl.

In a small saucepan, combine sugar, vegetable oil, cider vinegar, water, salt, and pepper. Heat over medium heat until boiling, stirring until sugar dissolves.

Pour the hot dressing over the bean and vegetable mixture and toss gently to combine.

Cover the bowl with plastic wrap and refrigerate for at least an hour.

Stir the salad before serving, adjusting salt and pepper as needed.