TM 9-2320-209-20-3-2 13-22. AIR BRAKE VALVE REMOVAL AND REPLACEMENT. TOOLS: 1-inch wrench 7/8-inch wrench 1 1/4-inch wrench 15-inch adjustable wrench SUPPLIES: None PERSONNEL: One EQUIPMENT CONDITION: Truck parked, engine off, handbrake a. Preliminary Procedure. Vent air system pressure. Refer to b. Removal. set. para 13-20. 1. Turn valve handle (1) to the on (down) position. 2. Using 1-inch wrench, unscrew coupling (2) and hose (3). GO TO FRAME 2 13-162