Charging the System

Fig. 4 System Charging Valve Connections:

WARNING: Never remove a gauge line from its adapter when line is connected to the A/C system. Always remove the line adapter from the service fitting to disconnect a line. Do not remove charging hose at the gauge set while attached to the service low-side fitting. This will result in a complete discharge of the system due to the depressed schrader valve in service low-side fitting and may cause personal injury due to escaping refrigerant.
1. Open source valve and allow 1 lb. of liquid R12 or R134a to flow into system through low-side service fitting, Fig. 5.
2. As soon as 1 lb. has been added to system, start engine, set A/C control to upper outlets, temperature lever to Max cold, blower speed on high and push A/C compressor button to the On position (button should illuminate).
3. Slowly draw in remainder of refrigerant charge.
4. Turn off source valve and run engine for 30 seconds to clear lines and gauges.
5. With engine running, remove the charging low-side hose adapter from the suction pipe service fitting. Remove quickly to avoid excess refrigerant escaping from the system.
6. Ensure an O-ring seal is inside of caps before installation, because cap is primary seal for A/C service fittings. Failure to tighten cap will result in refrigerant leakage.
7. Install protective caps on service fittings and hand tighten.
8. Turn engine off, then check system for leaks with electronic leak detector.

DRUM METHOD
Place R134a drum on scale and note total weight before charging. Watch scale during charging to determine amount of R134a used.
1. Connect manifold gauge set as follows:
a. Connect low pressure gauge hose to low pressure service fitting on suction pipe at rear of compressor, Fig. 5. Do not connect high pressure line to A/C system.
b. Connect center hose to R134a source.
2. Open valve on drum to start flow of refrigerant.

CHARGING STATION METHOD
Follow charging station manufacturer's instructions with the following exceptions:
1. Do not connect high pressure line to air conditioning system.
2. Keep high pressure valve on the charging station closed at all times.
3. Perform the entire evacuation and charge procedure through the low-side pressure service fitting on the suction pipe, Fig. 5.
4. Following these procedures will prevent accidental high-side vehicle system pressure being subjected to the charging station in the event an error is made in valve sequence during compressor operation to pull in the R134a charge.