System Evacuation

The ACR4 unit tank must contain sufficient R-134a refrigerant for A/C system charging. Check the amount of refrigerant in the tank by simultaneously pressing "RESET" and "ENTER" on the keypad to enter the diagnostic mode. Once in the diagnostic mode, press "7". When "7" is pressed, the ACR4 unit will display the amount of R-134a refrigerant available in the tank. If less than 3.6 kg (5 pounds) is displayed, add new refrigerant to the tank. Refer to the manufacturer's instructions for adding refrigerant.

1. With the high side and low side hoses connected to the vehicle A/C system, open both the high-side (red) and the low-side (blue) valves on the unit control panel.
2. Open both the red "GAS" (vapor) and the blue "LIQUID" valves on the tank.

Important

^ To remove all the air and properly dry the A/C system, the unit automatically goes to a pre-programmed evacuation time.
^ It is possible to evacuate longer. Press keys to enter time desired. New entry will show on the display. Press "ENTER," the display will blink indicating input of data (See Image).

3. Press "VACUUM" to start the vacuum pump.
The display counts down the vacuum time to zero to indicate operation time remaining. The display reads "RECYCLE" five seconds after the vacuum pump starts and continues while the process takes place.

Important

^ Automatic refrigerant recycling during each evacuation is a feature of the ACR4 system. No action is required by the technician.
^ The control panel ''MOISTURE INDICATOR" must be green during recycling verifying refrigerant moisture content is within, specifications. Yellow indicates a set condition requiring a filter/drier cartridge change. See he manufacturer instructions for this procedure.
^ Non-condensable gases (mostly air) are automatically vented from the tank during the recycling process. An audible sound of pressure release may he heard as this happens. This is a normal function.

4. At approximately the 12-minute mark on the display (pump has run for three minutes), press "HOLD/CONT" key to stop vacuum pump (See Image).
A. A "0" vacuum reading indicates a major system leak. Repair leak and restart evacuation procedure.
B. if a vacuum reading of 91-101 kPa (27-30 inches of Hg) is indicated, close the low-side and high-side valves. Observe the vacuum level for a few minutes as a leak check of the A/C system. If vacuum is not maintained, find and repair the A/C system leak before continuing.
C. If a vacuum reading of 91-101 kpa (27-30 inches of Hg) is maintained, open the high-side and low-side valves and press the "HOLD/CONT" key to restart the vacuum pump.
5. When the vacuum sequence has run the programmed time, the display shows "CPU" to indicate that evacuation is complete.

Important

^ The vacuum pump oil must be changed frequently.
^ When the pump has run for a total time of ten hours, the message "OIL" will flash on the control panel display as a remainder to change the oil.
^ If the "OIL" warning flashes during operation, press "CONT" and change the oil before the next operation. See the manufacturer instructions for this procedure.