The way I get those 6 caliper bracket bolts off is this.
I use a short 6point impact socket with a 3/4 in t bar that I slide a tight fitting cheater pipe over. Then depending on the specific location (some will loosen going up and that's when the floor jack works. Some loosen down then another bar and leverage works.)
I either slide a floor jack under the cheater pipe and jack it loose for the ones that loosen up or use another long bar, horizontal to the cheater, with its end up against a housing member creating as much leverage as nessessary by pushing down on those that loosen that way.
Do not be disappointed if your new tool is still insufficient to free them. It would not be the tool thats defective. May the force be with u.
BE VERY VERY CARFUL WHEN USING CHEATER BARS.
The bolt is still going to require a huge amount of force to get started loose and if any thing slips loose it the event of trying u can really hurt yourself bad in a whole variety of fashons. Make sure your noggin is nowhere in the line of fire.
Maybe your new tool will get them I hope it does.