TM-9-2320-387-24 HMMWV Direct Support & General Support Maintenance Manual Volume 2 Download
Page 913 of 1555
TM 9-2320-387-24-2 25 15. A/C SYSTEM SERVICING (Cont’d) -aManifold Gauge Set Removal 1 1. Ensure high-pressure gauge valve (21 and low-pressure gauge valve (1) on manifold gauge set (3) are in seated (clockwise) position. 2. If system was charged with refrigerant, wait several minutes after turning engine off for high and low sides to stabilize before performing next step. A charged A/C system is always pressurized at 20-30 psi (138-207 kPa). Hose connectors must be held firmly to avoid ends whipping back and damaging equipment. 3. Disconnect low-pressure gauge hose (6) and high-pressure gauge hose (41from service ports (8) and (9). 4. Install two caps (71 on service ports (8) and (9). c. Discharging System 1. Install manifold gauge set (refer to task a.). 2. Connect center hose (5) of manifold gauge set (3) to an approved recovery machine. NOTE l Do not allow refrigerant R-134a to escape too quickly. Refrigerant oil will escape. l When high- and low-pressure gauges read zero, the discharging procedure is complete. Allow machine to run for 5 minutes after gauges read zero. 3. Slightly turn high-pressure gauge valve (2) and low-pressure gauge valve (1) counterclockwise to permit refrigerant to slowly escape through center hose (5) until both gauges read zero. 4. Measure any significant accumulation of oil in discharge bottle and record for oil charging purposes. 5. Disconnect manifold gauge set (3) (refer to task b.). 25-40