TM-9-2350-311-20-1 Maintenance Manual for Volume 1 M109 Hull Download
Page 38 of 1275
TM 9-2350-311-20-1 1-17 EQUIPMENT OPERATION AND DESCRIPTION — CONTINUED 1-17.5 Cooling System a. b. c. d. e. f. g. h. i. Radiator (1) — cools the coolant flowing through it. Surge tank (2) — allows for overflow from the radiator (1) in this closed cooling system. The capacity of the surge tank and the radiator is 22 gal (83 L). Engine-driven coolant pump (3) — pulls coolant from the radiator (1) and distributes it to the engine and transmission oil coolers (4) and back to the radiator or surge tank (2). Engine and transmission oil coolers (4) — cools the oil within the engine and transmission by surrounding the oil cooler tubes with coolant. Inlet thermostat (5) — directs the flow of the coolant from the engine to different areas of the cooling system. If the engine is running hot enough to open the inlet thermostat, the coolant flow will be directed to the radiator (1) so it can be cooled. If the engine is running cool enough, the inlet thermostat will direct flow to the bypass thermostat (6) or surge tank (2). Bypass thermostat (6) — allows inflow from the inlet thermostat (5) and cooling crossover tube and directs it back to the engine-driven coolant pump (3) and to the oil coolers (4). Air intake grille (7) — allows air to be pulled into the engine compartment by the radiator fan assembly (8). Radiator fan assembly (8) — pulls in air through the air intake grille (7) across the engine and pushes the air through the radiator (1) ‘honeycomb.” The air is then discharged through the exhaust grille (9). Exhaust grille (9) — allows air pushed and pulled by the fan assembly (8) through the radiator (1) and back out of the engine compartment. 1-24