TM-9-2320-280-34 HMMWV Direct Support & General Support Maintenance Manual Download
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14-17. AIR-CONDITIONING SYSTEM SERVICING (Cont'd) 1. Charge A/C system (refer to task f.). 2. Make sure low pressure gauge valve (1) and high pressure gauge valve (2) on manifold gauge set (3) are turned clockwise to off position. 3. Turn two service valve shafts (6) counterclockwise to back-seated position. 4. Start engine and turn on A/C system (refer to TM 9-2320-280-10). Allow engine to idle for approximately ten to fifteen minutes. Stop engine. 5. Turn two service valve shafts (6) clockwise to front-seated position. NOTE • Do not allow refrigerant FR-12 or R-12 to escape too quickly. Refrigerant oil will escape. • When high pressure gauge and low pressure gauge read “zero”, the compressor is discharged. 6. Turn low pressure gauge valve (1) and high pressure gauge valve (2) counterclockwise slightly to permit refrigerant in the compressor (5) to slowly escape through center hose (4) until gauges read “zero”. 7. Close low pressure gauge valve (1) and high pressure gauge valve (2). 8. Remove fill plug (7) and O-ring (8) from compressor (5). Discard O-ring (8). 9. Look through fill plug (7) hole in compressor (5) and rotate front clutch plate (9) with ratchet and socket to position internal compressor parts, as shown. Planet plate should be positioned so that dipstick can be inserted to full depth. 10. Insert the dipstick to its stop position, as shown. The stop is the angle near the top of the dipstick. The point of the angle must be to the right, and the bottom surface of the angle must be flush with the surface of the filler hole. 11. Remove dipstick from compressor (5) and count number of increments oil level is up to on dipstick. 12. Oil level should be between six and eight increments on dipstick. Add or subtract oil as necessary to attain proper level. 13. Lubricate O-ring (8) with refrigerant oil and install O-ring (8) and fill plug (7) on compressor (5). Tighten fill plug (7) to 6-9 lb-ft (8-12 N•m). 14. Remove manifold gauge set (refer to task b.). g. Checking/Adding Refrigerant Oil NOTE • It is not necessary to check or add oil as routine maintenance. It is necessary to check oil when the evaporator, condenser, compressor, or receiver/dryer has been replaced, or there was an obvious oil leak. When a system is discharged, it is also necessary to replace any oil carried out with the refrigerant. • Vehicle must be on level ground. • FR-12 systems require different lubricating oil. TM 9-2320-280-34 14-100 Change 1 SERVICE VALVE IN FRONT-SEATED POSITION SERVICE VALVE IN BACK-SEATED POSITION