AB freight valve test rack

In an AB test rack having means for mounting an AB service portion with a duplex release valve and an AB emergency portion with a quick action exhaust port, a source of air under pressure, and valve means for connecting other ports of said portions to said source and to the atmosphere to carry out standard tests, the improvement comprising a manifold, a first quick connector for coupling, when actuated, said duplex valve of a mounted service portion to said manifold, said first connector including an air cylinder, means for connecting said air cylinder to said source, a connecting valve mounted for movement with said cylinder into a position engaging said duplex valve and having an interior path for conducting air exiting from said duplex valve to an outlet, and means for connecting said outlet to said manifold, a second quick connector for coupling, when activated, said quick action exhaust port of a mounted emergency portion to said manifold, said second connector including a second air cylinder, means for connecting said second cylinder to said source, a second connecting valve mounted for movement with said second cylinder into a position engaging said quick action exhaust port and having an interior path for conducting air exiting from said quick action exhaust port to an outlet, and means for connecting said outlet of said second connecting valve to said manifold, a muffler having an inlet and outlet and a plurality of aperture baffle plates therein defining a path between said inlet and outlet, and means for connecting said manifold to the inlet of said muffler.