TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 2 Download
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TM 9-2320-280-20-2 3-60. COOLING SYSTEM SERVICING This task covers: a. Depressurizing c. Preventive Cleaning b. Draining System d. Fillng System INITIAL SETUP: Tools Manual References General mechanic’s tool kit: TM 9-2320-280-10 automotive (Appendix B, Item 1) TM 9-2320-280-24P TM 750-254 Test Equipment TB 750-651 Radiator tester (Appendix B, Item 66) Equipment Condition Materials/Parts Hood raised and secured (TM 9-2320-280-10). Antifreeze (Appendix C, Item 12) General Safety Instructions Do not remove surge tank filler cap before releasing internal pressure. a. Depressurizing WARNING Do not remove surge tank filler cap before depressurizing system when engine temperature is above 190°F (88°C). Steam or hot coolant under pressure will cause severe burns. 1. If engine is hot, remove surge tank filler cap (1) by placing a thick cloth over cap (l). Press down and turn counterclockwise to its first stop to release internal pressure. 2. After pressure has escaped, press down and turn cap (1) counterclockwise again and remove. b. Draining System 1. If engine is hot, repressurize system (see a. of this task). NOTE Have drainage container ready to catch coolant. 2. Open draincock (4) and allow system to drain. 3. Close draincock (4). c. Preventive Cleaning 1. For preventive cleaning, refer to TB 750-651. 2. Test surge tank filler cap (1), refer to TM 750-254. d. Filling System NOTE The cooling system for the vehicles covered in this manual has a 26 qt (25 l) capacity. Continue filling and allow air to escape. Ensure surge tank coolant level is 3/4 full before securing filler cap. 1. Ensure radiator draincock (4) is closed and heater control valve (3) is open (pull “TEMP” knob on dash to “MAX” position). 2. Fill system with proper antifreeze solution. See table 3-1 for preparation of antifreeze solutions. 3-108