TM 5-2420-230-24-1
(10) After 28 inHg to 29 inHg (95 kPa to 98 kPa) vacuum has been reached and held for an additional 90 min., close
manifold gauge set (1) valves (2) and (3) completely.
(11) Turn OFF the vacuum pump. Refer to the vacuum pump OEM manual for operation instructions.
NOTE
Excessive vacuum loss is an indication of a possible leak in the system.
The maximum amount of vacuum loss in 5 min. must not be more than 2 inHg (7 kPa). Repair all
leaks and repeat Steps (1) through (11).
(12) If the vacuum loss does not exceed 2 inHg (7 kPa) in 5 min., the system is ready to charge.
d. Charging.
Contact with refrigerant can cause frostbite. Keep hands and face away to prevent personal injury.
Protective goggles must always be worn when refrigerant lines are opened, even if the gauges
indicate the system is empty.
Do not smoke when servicing air conditioners or wherever refrigerant gas may be present. Personal
injury or death can result from inhaling refrigerant through a lit cigarette.
Do not charge the air conditioning system with liquid refrigerant through the compressor suction ports.
This could seriously damage the compressor.
NOTE
Charging should be performed at air temperatures of 70 F (21 C) and above. Changes in ambient
air temperatures will affect the systems ability to take a charge and will vary gauge readings.
When adding a partial charge to the air conditioning system, if there is no evidence of air in the
system and there are no system leaks, it is not necessary to discharge and evacuate the A/C system.
Operating A/C system periodically during the off-season will lubricate the seals and reduce
possibilities of refrigerant loss.
Up to 7 oz. (200 g) of refrigerant loss per year is considered normal.
Steps (1) through (3) only need to be performed if a partial charge is being done.
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