TM 9-2320-209-20-3-2 (2) Air tube fittings. NOTE The air tube connecting nipple on the left side of chassis on truck M764 is used for this typical procedure. (a) Air tube connecting nipple FRAME 1 1. Using 11/16-inch combination box and open end box wrench, hold adapter fitting (1). Using 7/8-inch combination box and open end box wrench, unscrew and take off tube nuts (2 and 3). END OF TASK 13-152