TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
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2-156 Change 1 KNOWN INFO POSSIBLE PROBLEMS DIAGNOSTIC FLOWCHART TEST OPTIONS REASON FOR QUESTION KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION NO YES NO YES ENGINE COOLING IS THE COOLANT MIXTURE CORRECT? (SEE CHART ON PAGE 2-155.) IS THE COOLANT AT THE CORRECT LEVEL? START DRAIN & REFILL COOLANT FILL TO PROPER LEVEL 1 2 NONE COOLING COMPONENTS ENGINE FAN BELTS WATER PUMP AND PULLEY COOLANT MIXTURE TEST KIT NSN 6630-00-169-1506. The cooling system will not operate properly if the mixture is incorrect. Low coolant levels may cause overheating. COOLANT QUALITY OK COOLANT LEVEL COOLING COMPONENTS ENGINE FAN BELTS WATER PUMP AND PULLEY NO YES KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION 3 IS THE THERMOSTAT WORKING PROPERLY? REPLACE THERMOSTAT COOLANT OK THERMOSTAT GO TO 4, Page 2-158 FEEL FOR COOLANT IN UPPER RADIATOR HOSE WHEN ENGINE IS HOT, OR REMOVE THERMOSTAT. EXPOSE IT TO 190°F (88° C) AND SEE IF IT OPENS. COOLING COMPONENTS ENGINE FAN BELTS WATER PUMP AND PULLEY COOLANT TESTER NSN 6630-00-105-1418. An improperly functioning thermostat can cause operating temperatures that are either too hot or too cold. VISUAL INSPECTION. TM 9-2320-280-20-1