TM 9-2320-280-34
14-17. AIR-CONDITIONING SYSTEM SERVICING (R-12) (Cont'd)
f. Charging System
NOTE
If A/C system requires replacement of a major component or has
been flushed, 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-12 source to center hose (5) of manifold gauge set (3).
3.
Open refrigerant R-12 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) Loosen center hose (5) at manifold gauge set center port (7) slightly 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 valve ports at compressor.
(d) Turn high pressure gauge valve (2) and low pressure gauge valve (1) clockwise to off position.
5.
Turn service valve shafts (8) clockwise to mid-seated position.
6.
Connect STE/ICE-R (TM 9-2320-280-20) to obtain engine RPM reading.
WARNING
Make sure 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.
7.
Start engine and set engine speed to 1500 rpm with hand throttle (TM 9-2320-280-10).
8.
Turn on A/C system (TM 9-2320-280-10) and blower fans on high speed.
NOTE
Keep refrigerant container upright at all times so refrigerant
enters system as a gas.
The A/C system has a 1-3/4 lb (0.794 kg) capacity.
9.
Open low pressure gauge valve (1) on manifold gauge set (3) until system is fully charged
10.
Close low pressure gauge valve (1) on manifold gauge set (3).
11.
Return hand throttle to normal idle (TM 9-2320-280-10).
12.
Stop engine (TM 9-2320-280-10).
13.
Remove refrigerant R-12 source from center hose (5) of manifold gauge set (3).
14.
Perform task g.
14-98
Change 2
