Bring a large pot of salted water to a rolling boil. Add rotini pasta and cook until al dente, about 8-10 minutes. Drain and rinse under cold water.

In a large mixing bowl, combine mayonnaise, dill pickle juice, yellow mustard, sugar, celery salt, and pepper. Whisk for about 1-2 minutes until smooth.

Fold the cooled pasta into the dressing, add chopped dill pickles, grated cheddar cheese, celery, and red onion. Stir until mixed.

Cover with plastic wrap or transfer to an airtight container. Chill for at least 2 hours, preferably overnight.

Before serving, stir gently and keep chilled until served.