‘Tallet’s Gym’, one of the Real Steel filming locations, was a fire-station – the former Detroit Fire Department HQ, in the heart of downtown Detroit. Another filming location "Crash Palace" is the old Model T factory in Highland Park that was building Ts in 1910

From 1929 to 1949 it was the fire dept HQ, and was the city’s first firehouse designed for motorized – rather than horse-drawn – fire equipment. Then it was the MGM Grand casino, but never was put up for sale until 2012. 

The firehouse was designed to house more than 500 firefighters on its second through fifth floors

The site was used by the fire dept constantly since 1840, and is across the street from Cobo hall

Other filming sites were the former Belle Isle Nature Zoo, and the Parkway Motel on I 75

What might be a surprise is that the whole movie was filmed in Michigan, and not Texas where the story is set. 

https://movie-locations.com/movies/r/Real-Steel.php#:~:text=That's%20because%20it's%20a%20fire,Superman%3A%20Dawn%20Of%20Justice)

https://historicdetroit.org/galleries/detroit-fire-department-headquarters-photos

https://www.mlive.com/business/detroit/2012/08/detroit_fire_departments_downt.html

https://historicdetroit.org/buildings/detroit-fire-department-headquarters-former

https://www.detroitnews.com/picture-gallery/business/retail/2014/08/25/historic-detroit-fire-hq-to-become-luxury-hotel/14588131/

https://www.traditionalbuilding.com/projects/blackberry-systems-case-study-the-detroit-foundation-hotel

https://www.themovieblog.com/2011/10/review-real-steel/

I posted about the truck in 2011 https://justacarguy.blogspot.com/2011/10/movie-real-steel-is-awesome-and-has.html