TM 9-2320-280-34
14-27.1. AIR-CONDITIONING SYSTEM SERVICING (R-134a) (Cont'd)
b. Manifold Gauge Set Removal
1.
Turn service valve shafts (10) counterclockwise to back-seated position.
2.
Ensure high-pressure gauge valve (2) and low-pressure gauge valve (1) on manifold gauge set (3)
are in (seated, clockwise) OFF position.
3.
If system was charged with refrigerant, wait several minutes after turning engine off for high and
low sides to stabilize before performing next step.
CAUTION
A charged A/C system is always pressurized at 70-80 psi
(483-552 kPa). Hose connectors must be held firmly to avoid ends
whipping back and damaging equipment.
4.
Disconnect low-pressure gauge hose (6) and high-pressure gauge hose (4) from service ports (8) and (9).
5.
Install two caps (7) on service ports (8) and (9).
c. Discharging System
1.
Turn service valve shafts (10) counterclockwise to back-seated position.
2.
Install manifold gauge set (refer to task a.).
3.
Connect center hose (5) of manifold gauge set (3) to an approved recovery machine.
NOTE
Do not allow refrigerant R-134a to escape too quickly.
Lubricating oil will escape.
When high- and low-pressure gauges read zero, the discharging
procedure is complete. Allow machine to run for 5 minutes after
gauges read zero.
4.
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.
5.
Measure any significant accumulation of oil in discharge bottle and record for oil charging
purposes.
6.
Turn service valve shafts (10) counterclockwise to back-seated position.
7.
Disconnect manifold gauge set (3) (refer to task b.).
8.
Turn service valve shafts (10) counterclockwise to mid-seated position.
14-134.4
Change 2
