Place potatoes in a large pot of lightly salted water. Boil for 15 to 20 minutes or until tender. Drain well.
Cut the potatoes in half (cut larger potatoes in quarters so all pieces are about the same size). Place the potatoes, onion, eggs and pickles in a large bowl. Stir gently to combine.
In a small bowl, whisk together mayonnaise, brine, garlic salt, pepper and dill. Spoon mayo mixture into potato mixture and stir gently.
Cover and refrigerate 4 hours or overnight.