TM 9-2320-209-10-1 c. Fording, Water Tank Trucks. 1. Before fording, open rear compartment doors and drain delivery lines, manifold pipes and delivery pump. (a) Push 400 gallon and 600 gallon compartment levers (1) forward to closed position. (b) Turn to left and take dust covers (2) off of delivery line discharge and suction valves (3). (c) Turn delivery line discharge and suction valve knobs (4) left all the way, to open valves. GO TO FRAME 2 4-413