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TM-9-2320-280-34 HMMWV Direct Support & General Support Maintenance Manual Download

Page 698 of 1258

14-17. AIR-CONDITIONING SYSTEM SERVICING (Cont'd) NOTE If A/C system requires replacement of a major component or has been flushed, refrigerant oil must be added to system to compensate loss (refer to task g.). 1. Evacuate A/C system (refer to task e.). 2. Connect refrigerant FR-12 or R-12 source to center hose (5) of manifold gauge set (3). 3. Open refrigerant FR-12 or R-12 source to allow refrigerant to flow into center hose (5). 4. Purge center hose (5), low pressure hose (6), and high pressure hose (4) as follows: (a) Loosen center hose (5) at manifold gauge set center port (7) slightly until refrigerant escapes, then tighten hose (5). (b) Open high pressure gauge valve (2) and low pressure gauge valve (1) to allow refrigerant to flow into high pressure hose (4) and low pressure hose (6). (c) Purge high pressure hose (4) and low pressure hose (6) at service valve ports at compressor. (d) Turn high pressure gauge valve (2) and low pressure gauge valve (1) clockwise to off position. 5. Turn service valve shafts (8) clockwise to mid-seated position. 6. Connect STE/ICE-R (TM 9-2320-280-20) to obtain engine RPM reading. WARNING Make sure high pressure gauge valve is in closed position on manifold gauge set during charging. Failure to do so will cause compressor to build pressure in refrigerant container, causing injury to personnel or damage to equipment. 7. Start engine and set engine speed to 1500 rpm with hand throttle (TM 9-2320-280-10). 8. Turn on A/C system (TM 9-2320-280-10) and blower fans on high speed. NOTE • Keep refrigerant container upright at all times so refrigerant enters system as a gas. • The A/C system has a 1-3/4 lb (0.794 kg) capacity. 9. Open low pressure gauge valve (1) on manifold gauge set (3) until system is fully charged (table 2-2). 10. Close low pressure gauge valve (1) on manifold gauge set (3). 11. Return hand throttle to normal idle (TM 9-2320-280-10). 12. Stop engine (TM 9-2320-280-10). 13. Remove refrigerant FR-12 or R-12 source from center hose (5) of manifold gauge set (3). 14. Perform task g. f. Charging System TM 9-2320-280-34 14-98 Change 1