Brakes don't work on my Logitech Driving Force GT

Acceleration works, reverse works, but when I press the brake pedal, the brake lights come on but the car doesn't slow down. Everything else works. They aren't set to combined in BNG nor Logitech's software. BNG recognizes the pedals as 2 separate axes and sees when I press gas (y axis) or brake (rz axis). Help?

Edit: Narrowed down the problem. when using djplopper's mega config and choosing one of his modded Gavril D-Series trucks, the brakes don't work. But it only happens on that particular mod. Weird. Disregard.