TM 9-2320-209-20-3-2 13-40. AIR BRAKE CUTOFF COCKS AND COUPLINGS REMOVAL AND REPLACEMENT (TRUCK M764). TOOLS: 1 3/8-inch wrench 3/4-inch wrench 5/8-inch wrench 1 1/4-inch wrench 10-inch pipe wrench 9/16-inch wrench (2) 1 1/2-inch wrench Vise SUPPLIES: None PERSONNEL: One EQUIPMENT CONDITION: Truck parked, engine off, handbrake set. a. Preliminary Procedures. (1) Vent air system pressure. Refer to para 13-20. (2) Remove quick-disconnect coupling half. Refer to para 13-37. 13-275