Brake Popping Noise problems of the 2015 Ford F-250

While travelling in morning rush stop and go traffic, in austin, texas I had to come to a complete stop. The truck would not stop until I applied considerable brake pressure. I came within 6 inches of the vehicle in front. I was travelling at approximately 1 to 2 mph at the time. On the return trip in the evening rush hour it was also stop and go. I had to come to a complete stop but the truck would not stop. I had to put as much brake pressure as I could to slow the truck (doing 1 mph or less). I still tapped the vehicle in front. At the time I was trying to stop the truck, I heard the engine rpm rev up and a popping noise from the engine. Taking the truck to the dealer for a check up on the issue.