Operation Procedure for Refrigerant Charge: 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 refrigerant through low pressure side of A/C system after the initial charge is performed from the high pressure side with the engine stopped.
Never charge refrigerant through high pressure side of A/C system with engine running.
Do not charge refrigerant 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 refrigerant charge.
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 refrigerant charge. Reversing in direction causes liquid refrigerant to enter compressor, causing troubles, such as compression of liquid refrigerant and the like.

NOTE: The air conditioning system contains HFC-134a (R-134a).
Described here is a method to charge the air conditioning 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.

The initial charge of the A/C system is performed through 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 if 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. Then, open refrigerant container valve (4) to purge the charging line.
Open the high pressure side valve (5) and charge refrigerant to system.
After a while, open the low pressure side valve (6) and close the high pressure side valve.
WARNING: Make sure that high pressure side valve is closed securely.
Start engine and keep engine speed at 1500 r/min, and then operate A/C system.
Charge A/C system with refrigerant in vapor state. At this time, refrigerant container should be held upright.

Fig 1: Connecting Low Charging Hose And High Charging Hose Of Manifold Gauge Set
Courtesy of SUZUKI OF AMERICA CORP.
When refrigerant container (1) is emptied, use the following procedure to replace it with a new refrigerant container.
1. Close low pressure valve.
2. Replace empty container with a refrigerant container which has been charged with refrigerant. When using refrigerant container tap valve (2), use the following procedure for replacement.
  1. Retract needle (3) and remove refrigerant container tap valve by loosening its plate nut (4).
  2. Install the refrigerant container tap valve to a new refrigerant container.
    
    Fig 2: Identifying Needle And Plate Nut
    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 (1), and then loosen (open) plate nut (2) slightly.
  2. Open low pressure side valve (3) of manifold gauge set (4) a little.
  3. As soon as refrigerant comes out with a "hiss" through a clearance between refrigerant container and tap valve, tighten plate nut as well as low pressure side 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 Low Pressure Side Valve Of Manifold Gauge Set
    Courtesy of SUZUKI OF AMERICA CORP.

After the system has been charged with specified amount of refrigerant or when low pressure gauge (1) and high pressure gauge (2) have indicated the following specified value, close low pressure side valve (3) on manifold gauge set (4).

Specified amount of refrigerant

430 ± 20 g (15.2 ± 0.7 oz))

Low side and high side pressure example (CVT model)

HIGH PRESSURE GAUGE SPECIFICATIONS

Gauges should read as follows when ambient temperature is 30 °C (86 °F).
Pressure on high pressure gauge	1220 - 1550 kPa 12.4 - 15.8 kgf/cm² 176.9 - 224.8 psi
Pressure on low pressure gauge	240 - 350 kPa 2.4 - 3.6 kgf/cm² 34.8 - 50.8 psi

Low side and high side pressure example (M/T model)

LOW SIDE AND HIGH SIDE PRESSURE SPECIFICATIONS

Gauges should read as follows when ambient temperature is 30 °C (86 °F).
Pressure on high pressure gauge	1200 - 1820 kPa 12.2 - 18.6 kgf/cm² 174.0 - 264.0 psi
Pressure on low pressure gauge	250 - 350 kPa 2.5 - 3.6 kgf/cm² 36.3 - 50.8 psi

Fig 4: Checking Low Side And High Side Pressure

Courtesy of SUZUKI OF AMERICA CORP.