Operation Procedure for Charging A/C with Refrigerant: Charge

CAUTION:

Because the sight glass is not used for this A/C system, do not perform an additional charge to the A/C system. To charge the proper amount of refrigerant, recover and evacuate the A/C system first. And then, charge the proper amount of refrigerant into the A/C system.
Always charge through low pressure-side of A/C system at after the initial charging is performed from the high-pressure side with the engine stopped.
Never charge to high pressure-side of A/C system with engine running.
Do not charge while compressor is hot.
When installing tap valve to refrigerant container to make a hole there through, carefully follow directions given by manufacturer.
A pressure gauge should always be used before and during charging.
The refrigerant container should be emptied of refrigerant when discarding it.
The refrigerant container should not be heated up to 40 °C (104 °F) or over.
Refrigerant container should not be reversed in direction during charging. Reversing in direction causes liquid refrigerant to enter compressor, causing troubles, such as compression of liquid refrigerant and the like.

NOTE: The A/C system contains HFC-134a (R-134a).
Described here is a method to charge the A/C system with refrigerant from the refrigerant service container.
When charging refrigerant recovered by using the refrigerant and recycling equipment (when recycling refrigerant), follow the procedure described in the equipment manufacturer's instruction manual.

Charge proper amount of refrigerant accurately in accordance with the following procedure.

Specified amount of refrigerant

530 ± 30 g (18.6 ± 1.0 oz)

The initial charging of the A/C system is performed from the high-pressure side with the engine stopped.

And next, this method must be followed by charging from the low-pressure side with the engine running.

Check to make sure that hoses are routed properly after evacuating the system.
Connect low charging hose (1) and high charging hose (2) of the manifold gauge set (3) in position. Thus open refrigerant container valve (4) to purge the charging line.
Open the high-pressure side valve (6) and charge refrigerant to system.
After a while, open the low-pressure side valve (5) and close the high-pressure side valve (6).
WARNING: Make sure that high pressure-side valve is closed securely.

Fig 1: Identifying Low/High Charging Hose, Manifold Gauge Set And Refrigerant Container Valve
Courtesy of SUZUKI OF AMERICA CORP.
Start engine and keep engine speed at 1,500 rpm. Then, operate A/C system.
Charge A/C system with refrigerant in vapor state. At this time, refrigerant container should be held upright.
When refrigerant container (3) is emptied, use following procedure to replace it with a new refrigerant container (3).
1. Close low pressure valve.
2. Replace empty container (3) with a refrigerant container which has been charged with refrigerant.
  When using refrigerant container tap valve (4), use the following procedure for replacement.
  1. Retract needle (1) and remove refrigerant container tap valve (4) by loosening its plate nut (2).
  2. Install previously-removed refrigerant container tap valve (4) to a new refrigerant container (3).
    
    Fig 2: Identifying Needle, Refrigerant Container Tap Valve, Plate Nut And Refrigerant Container
    Courtesy of SUZUKI OF AMERICA CORP.
3. Purge any air existing in center charging hose.
  When using refrigerant container tap valve, use the following procedure to purge air.
  1. Once fully tighten refrigerant container tap valve and then loosen (open) plate nut slightly.
  2. Open low pressure valve of manifold gauge set a little.
  3. As soon as refrigerant comes out with a "hiss" (1) through a clearance between refrigerant container and tap valve, tighten plate nut as well as manifold gauge set low pressure valve.
  4. Turn handle of tap valve clockwise so that its needle is screwed into the new container to make a hole for refrigerant flow.
    
    Fig 3: [Identifying Clearance Between Refrigerant Container And Tap Valve]
    Courtesy of SUZUKI OF AMERICA CORP.

After the system has been charged with specified amount (530 ± 30 g) of refrigerant or when low pressure gauge and high pressure gauge have indicated the following specified value, close low pressure side valve on manifold gauge set.

Low side and high side pressure example

LOW SIDE AND HIGH SIDE PRESSURE CHART

Gauges should read as follows when ambient temperature is 30 °C (86 °F)
J24B model	Pressure on high pressure gauge	1400 - 1595 kPa (14.3 - 16.3 kg/cm2) (203 - 231 psi)
J24B model	Pressure on low pressure gauge	260 - 374 kPa (2.7 - 3.8 kg/cm2) (37.7 - 54.2 psi)
N32A model	Pressure on high pressure gauge	1270 - 1540 kPa (13.0 - 15.7 kg/cm2) (184 - 223 psi)
N32A model	Pressure on low pressure gauge	260 - 352 kPa (2.7 - 3.6 kg/cm2) (37.7 - 51.0 psi)