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 (41 from 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.).
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