In a large stock pot with steamer insert on high heat, steam the potatoes whole (5 lbs takes about 50 min- remove smaller potatoes as they will cook faster. Let cool. Cut into 1 inch pieces leaving skin on but, discard skin that peels off easily while cutting.
In a medium bowl, mix mayonnaise, dill pickle brine, mustard, vinegar, sugar, salt, pepper, and garlic.
In a very large bowl, add cut potatoes, dill, chopped celery, eggs, and mayo mixture. Mix well and store in a covered container for several hours or overnight (is best.) Garnish with celery leaves.
If you are limited with time, you may boil potatoes for 30 minutes or so depending upon the size of the potatoes. When a fork comes out rather easily, the potatoes are done. Do not overcook or they will get mushy.