A test connector adapter plate for use with a pipe bracket portion of a freight brake control valve of a railway freight vehicle and with a portable automated single car brake tester. The pipe bracket portion having four test ports vertically disposed on a front side of such pipe bracket portion for single car brake testing. These test ports are fluidly connected to passageways within the pipe bracket for communicating fluid pressure with brake pipe, brake cylinder, emergency reservoir and auxiliary reservoir, respectively. A first member of the test connector adapter plate is engagable with the test ports on such front side of the pipe bracket portion for accessing the passageways respectively communicating to brake pipe, brake cylinder, emergency reservoir and auxiliary reservoir and are fluidly connected to respective passageways within the adapter plate. A second member of the test connector adapter plate is a manifold with access ports for providing fluid communication from brake pipe, brake cylinder, emergency reservoir and auxiliary reservoir to test receiver of the portable automated single car brake tester. The manifold of the second member of the adapter plate is directed to provide access on an axis perpendicular to that of the first member of the adapter plate so as to provide at. least one of a top and a bottom access for the portable automated single car brake tester.