TM 9-2320-363-34-1
AIR CONDITIONING SYSTEM REFRIGERANT (R-134a) MAINTENANCE
(CONT)
NOTE
Before charging, the system must be recovered and evacuated with the recovery and
recycling station connected to the service and discharge port connections.
1 .
OBTAIN ENOUGH REFRIGERANT TO FULLY CHARGE THE SYSTEM. SET THE TANK ON A
SCALE AND WEIGH IT SO THAT THE CORRECT AMOUNT OF REFRIGERANT ENTERS THE
SYSTEM. THIS PREVENTS OVERCHARGING, WHICH COULD DAMAGE THE COMPRESSOR.
2.
CHARGE THE REFRIGERANT SYSTEM.
NOTE
If equipped with a recovery, recycling, and recharging station, charge the system on the high
side following the manufacturers’s instructions. If charging from a bulk container, do the
following steps (a-d).
a.
TURN THE TANK (BULK CONTAINER) UPSIDE DOWN. WITH THE ENGINE OFF,
OPEN THE HIGH-SIDE HAND VALVE. DO NOT OPEN THE LOW-SIDE HAND
VALVE.
b.
ALLOW REFRIGERANT TO ENTER THE SYSTEM UNTIL THE CORRECT CHARGE
(BY WEIGHT) HAS ENTERED. THEN, CLOSE THE HIGH-SIDE HAND VALVE.
C.
START THE ENGINE AND RUN IT AT 1500 RPM. SET THE CAB AIR
CONDITIONER CONTROLS AT MAXIMUM COOLING AND FAN SPEED; THE
REFRIGERANT COMPRESSOR MUST ENGAGE.
d.
IF A FULL CHARGE DID NOT ENTER THE SYSTEM, PLACE THE TANK (BULK
CONTAINER) IN THE UPRIGHT POSITION, THEN OPEN THE LOW-SIDE VALVE
TO DRAW VAPOR INTO THE SYSTEM; LEAVE THE VALVE OPEN UNTIL THE
CORRECT WEIGHT OF REFRIGERANT HAS ENTERED THE SYSTEM, THEN
CLOSE THE LOW-SIDE VALVE.
NOTE
If refrigerant is slow to enter the system because of low outside temperatures, vaporization
can be quickened by placing the refrigerant tank in a tub of warm water, no warmer than
125°F (52°C).
3.
DISCONNECT THE HIGH-SIDE HOSE. WITH THE ENGINE RUNNING, OPEN THE LOW-SIDE
AND HIGH-SIDE HOSE VALVES TO RECOVER THE REFRIGERANT FROM THE LINES.
4.
SHUT DOWN THE ENGINE.
NOTE
Follow-on Maintenance:
Leak test air conditioning system (TM 9-2320-363-20).
Check operation of air conditioning system (TM 9-2320-363-10).
11.1-8
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