Do NOT run the engine with a vacuum pump in operation or with a vacuum present within the A/C system. Failure to follow this caution will result in serious A/C compressor damage.
Special effort must be used to prevent moisture from entering the A/C system oil. Moisture in the oil is very difficult to remove and will cause a reliability problem with the A/C compressor.
When connecting the service equipment coupling to the line fitting, verify that the valve of the coupling is fully closed. This will reduce the amount of effort required to make the connection.
Recover the refrigerant system.
With the engine OFF, connect a suitable charging station, refrigerant recovery machine or a manifold gauge set with vacuum pump and refrigerant recovery. Do not operate the engine with a vacuum on the A/C system.
Open the suction and discharge valves and start the vacuum pump. The vacuum pump should run a minimum of 45 minutes prior to charge to eliminate all moisture in system. When the suction gauge reads to the lowest degree of vacuum possible (approximately -88 kPa (- 26 in. Hg) or greater) for 30 minutes, close all valves and turn off vacuum pump. If the system fails to reach specified vacuum, the refrigerant system likely has a leak that must be corrected. If the refrigerant system maintains specified vacuum for at least 30 minutes, start the vacuum pump, open the suction and discharge valves. Then allow the system to evacuate an additional 10 minutes.
Close all valves. Turn off and disconnect the vacuum pump.
Charge the refrigerant system.
R-134a service equipment or vehicle A/C system should not be pressure tested or leak tested with compressed air. Mixture of air and R-134a can be combustible at elevated pressures. These mixtures are potentially dangerous and may result in fire or explosion causing property damage and possible serious or fatal injury.
If the A/C system refrigerant charge is empty or low, a leak in the A/C system is likely. Visually inspect all A/C lines, fittings and components for an oily residue. Oil residue can be an indicator of an A/C system leak location.
The only way to correctly determine if the A/C system is fully charged with refrigerant to perform the A/C Performance Test.
Evacuate the refrigerant system to the lowest degree of vacuum possible (approximately -88 kPa (-26 in. Hg) or greater vacuum). Determine if the system holds a vacuum for 15 minutes. If vacuum is held, a leak is probably not present. If system will not maintain vacuum level, proceed to .
Prepare and dispense 0.284 kilograms (10 ounces) of R-134a refrigerant into the evacuated refrigerant system and proceed to of the System Low procedure.
Position the vehicle in a wind-free work area. This will aid in detecting small leaks.
Operate the heating-A/C system with the engine at idle under the following conditions for at least 5 minutes.
A leak detector only designed for R-12 refrigerant will not detect leaks in an R-134a refrigerant system.
Doors or windows open
Transaxle in Park or Neutral with the parking brake set (depending on application)
A/C-heater controls set to outside air, full cool, panel mode, high blower and with A/C compressor engaged
Shut the vehicle off and wait 2-7 minutes. Then use an electronic leak detector that is designed to detect R-134a refrigerant and search for leaks. Fittings, lines or components that appear to be oily usually indicate a refrigerant leak. To inspect the A/C evaporator for leaks, insert the leak detector probe into the drain tube opening or an air outlet. A dye for R-134a is available to aid in leak detection. Use only Chrysler approved refrigerant dye.