Volvo VN semi truck pass through air line leak (Volvo Truck Performance Group on Facebook)

The sensors i mentioned are actually pressure sending units for your dash gauges. You may also need an airline plug, like i figured out. I’m assuming one of the open interior ports would emit air when i applied the brake pedal. Since my truck has no gauge for pressure applied, i plugged it. Dealer sells them. Check out Volvo Truck Perfomance Group on Facebook for more Volvo truck help!!