TM 9-6115-624-BD
CHAPTER 6
COOLING SYSTEM
BDAR FIXES SHALL BE USED ONLY IN COMBAT OR FOR TRAINING
AT THE DISCRETION OF THE COMMANDER
(AUTHORIZED TRAINING FIXES ARE LISTED IN APPENDIX E)
IN EITHER CASE DAMAGES SHALL BE REPAIRED BY STANDARD
PROCEDURES AS SOON AS PRACTICABLE
Section I. INTRODUCTION
6-1.
Scope. Cooling system problems may be indicated by a variety of faults. Typically the operator's indicator
panel will show overheating.
6-2.
Assessment Procedure.
a. Air Cooling System Assessment.
Air cooling system assessment procedures are structured using the logic
process shown in figure 6-1.
b. Liquid Cooling System Assessment. Liquid cooling system assessment procedures are structured using the logic
process shown in figure 6-2.
6-3.
Repair Procedure Index.
Damage
Paragraph
Shrouds, Ducts, Engine Compartment Cover, Air Cooling, Damaged .................................................
Coolant Substitutes .............................................................................................................................
Thermostat, Stuck ..............................................................................................................................
Engine Coolant, Frozen ......................................................................................................................
Radiator, Leaking ...............................................................................................................................
Hose Clamp, Broken ...........................................................................................................................
Hose, Leakage ....................................................................................................................................
Hose, Collapse ...................................................................................................................................
Hose Improvisation (Low Pressure) ....................................................................................................
Section II. AIR COOLING SYSTEMS
6-4.
General. Cooling system failures can result in engine failure and therefore must be dealt with if the engine is
expected to operate for any length of time. Cooling system problems most often are indicated on the operator's
instrument panel. While temporary overheating indications may result from excessive workload on the engine, repeated
overheating indication or constant indication of overheating is almost always followed by a major cooling problem.
6-5.
Shrouds, Ducts, Engine Compartment Cover, Air Cooling Damaged . Shrouds are used to direct the cooling
air over the hot engine. Bent or torn shrouds will upset the flow-of air and cause hot spots to occur which can cause
internal engine failures. The engine compartment is designed to direct airflow via the shrouds and ducts and if damaged,
can also cause hot spots or excessive noise. Torn shrouds can be bent back into shape and patched with sheet metal,
epoxy kits or tape to restore the proper air flow. At a minimum, they must be bent to prevent contact with moving
components. If the existing shrouds cannot be repaired, new shrouds must be fabricated from sheet metal. The same
applies to engine compartments, covers, and ducts.
6-1
