Classification: Reference: Date: HA00-001 NTB00-026 March 13, 2000 ACR4 REFRIGERANT MACHINE MAINTENANCE APPLIED VEHICLES: All Nissan Vehicles with R-134a Air Conditioning SERVICE INFORMATION To ensure accurate air conditioning system diagnosis and repair, it is critical that periodic maintenance be performed on your refrigerant charging equipment (ACR4 machine) and that proper operating techniques be used. Additionally, as refrigerant charge amounts continue to become smaller, it is vital that your refrigerant charging equipment be as accurate as possible. SERVICE PROCEDURE Use the information listed under the Maintenance section of this bulletin to tune-up your ACR4 machine to keep it operating at top performance. Refer to information listed under Operational Tips to ensure the highest level of charging accuracy when using the ACR4 machine. IMPORTANT: ACR4 maintenance should be conducted following the manufacture s instructions and recommended schedule. For details about performing ACR4 maintenance, refer to the ACR4 Operating Instruction Manual (Tech-Mate P/N J39500-7). Additional information related to ACR4 maintenance and operation is available in the May 1998 edition of Tech Talk and SIR video #57. The ACR4 Operating Instruction Manual can be ordered from Tech-Mate by calling 800-662-2001. NOTE: A maintenance kit is available for the ACR4 machine through Tech-Mate (P/N J- 39500-MAINT). The kit includes: vacuum pump oil, a desiccant/filter and two o-rings (for the desiccant/filter). The ACR4 Maintenance Kit can be ordered from Tech-Mate by calling 800-662-2001. 1/5
Maintenance Vacuum Pump Oil Change the vacuum pump oil every 10 hours of operation (when display reads OIL ) or sooner if contamination is seen through the sight glass (see Figure 1). Filter/Dryer Figure 1 Change the filter/dryer (see Figure 2) when 300lbs of refrigerant (approximately 150 cars) has been recovered (display reads CH-F ) or sooner if the moisture indicator does not turn green during recycling. Figure 2 ACR4 Leak Check Check the ACR4 for leaks every 3 months or as specified by state or local laws. Weight Scale Platform Securing Screw Make sure the weight scale platform securing screw is properly tightened. 2/5
Weight Scale Accuracy Check the weight scale accuracy at a minimum of every 3 months (or sooner if the scale is suspected to be inaccurate). Use the following procedure to check the scale accuracy. 1. Simultaneously press the SHIFT/RESET and ENTER buttons to get into the diagnostic mode (see Figure 3). Figure 3 2. Press 6 on the key pad to display the approximate scale platform weight 3. Remove the tank from the weight scale platform (see Figure 4). Figure 4 4. With the weight scale platform empty, the display should read close to zero + - 0.2 lbs. If the reading is too low or too high, perform the scale calibration procedure listed below. 3/5
Weight Scale Calibration Check the weight scale calibration at a minimum of every 3 months (or sooner if the scale is suspected to be inaccurate). Use the following procedure to calibrate the weight scale. 1. Simultaneously press the SHIFT/RESET and ENTER buttons to get into the diagnostic mode. 2. Press 8787. The display will read A1. 3. Remove all weight from the scale. 4. Press 0, then press ENTER. The display will show 0.00 and then changes to A2. 5. Place a certified known weight (between 10 to 80 lbs) in the center of the scale platform. NOTE: A certified 10 lb weight is available from Tech-Mate (P/N J-42363). This item can be ordered from Tech-Mate by calling 800-662-2001. 6. Enter the weight using four digits (i.e., 10.00 for 10.00 lbs). 7. Press ENTER. The display will return to vacuum mode. 8. Simultaneously press the SHIFT/RESET and ENTER buttons. 9. Press 6. The display will show the weight on the scale platform. 10. Remove the weight from the scale platform. The display will return to 0.00. 11.Press the SHIFT/RESET button only (not ENTER ) to return to the program mode. NOTE: If the scale cannot be calibrated or another malfunction exists, call the SPX Robinair ACR4 Help Line at 800-822-5561 or contact another qualified facility for repair. Tank Certification The tank must be certified on the First Retest Date (stamped into the top of the tank handle) and every 5 years after the First Retest Date. This is according to DOT-4BA-400. NOTE: A qualified welding supply, fire extinguisher maintenance or refrigerant company can perform the certification. Operational Tips Tank Position Make sure the tank is properly positioned/seated (especially after moving the ACR4 machine) on the scale platform and that it does not touch surrounding components (such as the back bar, hoses, etc.). Also, make sure the weight scale platform securing screw is properly tightened. Residual Refrigerant Recover all residual refrigerant from the hoses before connection to the vehicle. Residual Refrigerant Oil Drain all refrigerant oil from the oil separator (see Figure 4) before recovering refrigerant. This prepares the oil separator to measure the amount of oil removed during the recovery process. 4/5
Disturbing the ACR4 Machine Do not disturb or touch the ACR4 machine when it is recovering or recharging as this will upset the weight scale and cause the machine to record an inaccurate recovery amount and/or dispence an incorrect charge. Transfer All Refrigerant to Vehicle Use the following steps to ensure all of the refrigerant charge is transferred to the vehicle s A/C system. 1. When the display shows CPL (charge is complete), close the control panel high side valve (both control panel high and low side valves should now be closed). 2. Start the vehicle and let the A/C run until the gauge readings stabilize. Check for cold air at the vents. 3. With the compressor running, close the high side (red) coupler valve (on the end of the high side hose) and disconnect it from the vehicle. 4. Open the control panel high and low side valves. This will allow the residual refrigerant to be drawn into the vehicle s A/C system through the low (blue) hose. 5. Close the low side (blue) coupler valve (on the end of the low side hose) and disconnect it from the vehicle. NOTE: If your dealership purchases R134a in small, disposable (12 oz) cans, do not charge the vehicle s A/C system with the can directly. Transfer the refrigerant from the small can to the ACR4 refrigerant tank (see page 17 of the ACR4 Operating Instruction Manual). Charging the A/C system directly from the 12 oz refrigerant can (using a can tap gauge set) will not properly control the weight of refrigerant being transferred. This will result in an overcharge or undercharge condition and improper A/C performance. 5/5