Abstract: A test connector for connecting an air brake test device to access ports of an air brake control valve device where such access ports are normally closed by check valves. A plurality of actuator devices corresponding in number to the access ports are provided in the test connector to unseat the check valves and conduct test air to the test device via central passages in the actuators. The actuators are piston operated in response to a pilot pressure received from a source of compressed air remote from the connector.

Abstract: A hinge assembly for a manual or automatic air brake valve test fixture that includes a secondary test plate to which a valve device to be tested is mounted from a front load position and then rotated to its usual side location for clamping to the primary test plate, thereby relieving the tester of physical strain encountered heretofore in mounting the valve in a side load position. The hinge assembly is spring-loaded to obtain even, face-to-face engagement of the mating surfaces of the primary and secondary test plates and thereby assure the integrity of the pressure seal therebetween.

Abstract: A disk brake actuator having a hydraulic slack-adjusting arrangement for maintaining a positive clearance between a brake shoe and a brake disk, includes a cylinder housing having disposed therein a brake-applying spring section, a hydraulic-operated release section, and an actuator piston spindle arrangement operably-connected to the spring section by way of a clutch arrangement. A flange, formed on the actuator piston, acts as a plunger during a brake application and draws a first amount of hydraulic fluid into a first storage area, such first amount corresponding in volumn to the clearance between the brake disk and brake shoe when a nonworn brake shoe is first used. Upon release of the brake, the actuator piston forces the hydraulic fluid back into a second storage area wherein is included a shuttle member movable with a shuttle chamber. Additional hydraulic fluid is drawn from a reservoir when actuator piston movement, beyond the original clearance value, occurs as a result of brake shoe wear.