ARMY TM 9-2815-253-24 AIR FORCE TO 38G1-93-2 MARINE CORPS TM 2815-24/3 SECTION V.  COOLING SYSTEM MAINTENANCE 3-8.  GENERAL. This section provides maintenance for cooling system components.  Components of cooling system not mentioned in this Section can be found in the end item maintenance manual. WARNING If the engine has been operating and coolant Is hot, allow engine to cool before you slowly loosen filler cap and relieve pressure from cooling system.  Failure to follow this procedure could result In personal Injury. 3-9.  THERMOSTAT. 3-9.1.  Removal. a. Remove negative battery cable. b. Drain coolant system.  Refer to end item maintenance manual. c. Loosen hose clamp and disconnect outlet hose from thermostat housing (3, FIGURE 3-4). d. Remove two capscrews (1), washers (2), thermostat housing (3), and gasket (4).  Discard gasket (4). e. Remove thermostat (5) from water pump. NOTE If thermostat is suspected of being defective, replace thermostat. 3-9.2.  Inspection. a. Inspect thermostat for excessive wear or damage. b. Inspect housing for cracks, corrosion, or other damage. 3-9.3.  Replacement. a. Replace thermostat if worn or damaged. b. Replace housing if badly corroded or damaged. 3-9.4.  Installation. a. Remove all covers. b. Clean any debris and traces of old gasket from thermostat housing (3, FIGURE 3-4) and water pump (11) mating surfaces.  Dry all surfaces. c. Install thermostat (5) in water pump. d. Install new gasket (4), thermostat housing (3), two washers (2), and capscrews (1). e. Connect outlet hose to thermostat housing (3) and secure with hose clamp. f. Service coolant system.  Refer to end item maintenance manual. 3-10.  WATER PUMP. 3-10.1.  Removal. a. Drain coolant system.  Refer to end item maintenance manual. b. Relieve fan belt tension. 3-15