Air Brakes and Train Handling Rules - Alaska Railroad

67 Car Equipment and ComponentsEmpty/Load Indicator. When the load is heavy enough to depressthe freight car truck springs:1. The freight car and the 1-inch metal wedge piece will movedownward.2. The trigger level roller will roll up the empty/load wedge andtrigger the slack adjuster to make a change in the piston travel.3. Usually the load will not be heavy enough to move the car downto the loaded position, and the piston travel will remain at 9inches.4. If the load is heavy enough to depress the springs and cause thetrigger level to move to the loaded position, the piston travel willshorten to 8 inches to provide more brake cylinder force forunder the load.F. WABCO TMXFigure 67-Q. WABCO TMX Truck Mounted Brake System.June 1, 1996 ARRC Air Brakes and Train Handling Manual 67-27