TM 9-2320-280-34
14-27.1. AIR-CONDITIONING SYSTEM SERVICING (R-134a) (Cont'd)
f. Charging System
NOTE
If A/C system requires replacement of a major component or has
been flushed, PAG lubricating 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 R-134a source to center hose (5) of manifold gauge set (3) or recover and
recycle unit.
3.
Open refrigerant R-134a 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. Slightly loosen center hose (5) at center port (7) of manifold gauge set (3) 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 ports on compressor.
d. Turn high-pressure gauge valve (2) and low-pressure gauge valve (1) clockwise to OFF position.
5.
Connect STE/ICE-R (TM 9-2320-280-20) to obtain engine rpm reading.
WARNING
Ensure 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.
6.
Start engine and set engine speed to 1,500 rpm with hand throttle (TM 9-2320-280-10).
7.
Turn on A/C system (TM 9-2320-280-10) and set blower fans on high speed.
NOTE
Keep refrigerant container upright at all times so refrigerant
enters system as a gas.
8.
Open low-pressure gauge valve (1) on manifold gauge set (3) until system is fully charged with
2 lb 10 oz of R-134a refrigerant (refer to table 2-2.1).
9.
Close low-pressure gauge valve (1) on manifold gauge set (3).
10.
Return hand throttle to normal idle (TM 9-2320-280-10).
11.
Stop engine (TM 9-2320-280-10).
12.
Remove refrigerant R-134a source from center hose (5) of manifold gauge set (3).
13.
If no lubricating oil is needed, turn service valve shafts (10) counterclockwise to back-seated
position and disconnect manifold gauge hoses (4), (5), and (6) from A/C system service ports (7), (8),
and (9). Install caps (11) on service ports. If lubricating oil is needed, perform task g.
14.
Turn service valve shafts (10) clockwise to mid-seated position.
14-134.10
Change 2
