Flushing (HP2)

Special Tools

• J 41447  Leak Detection Dye. See Special Tools .
• J 42220  Universal 12V Leak Detection Lamp
• J 43600  ACR 2000 Air Conditioning Service Center. See Special Tools .
• J 45268  Flush Adapter Kit. See Special Tools .

Flushing is intended to remove the following contaminants:

• Contaminated polyalkylene glycol (PAG) oil
• Desiccant, following a desiccant bag failure
• Overcharge of PAG oil
• Refrigerant contamination

IMPORTANT: Warmer engine or ambient temperature decreases the refrigerant recovery time during the A/C flush procedure.
1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging (Non-HP2)  or Refrigerant Recovery and Recharging (HP2) .
2. Remove the orifice tube. Refer to Expansion (Orifice) Tube Replacement .
3. Connect the A/C lines with the orifice tube removed.
4. Remove the A/C compressor. Refer to Air Conditioning Compressor Replacement (LLY/LMM)  or Air Conditioning Compressor Replacement (LU3)  or Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)  or Air Conditioning Compressor Replacement (HP2) .
5. Inspect the end of the suction hose for a suction screen.
6. Remove the suction screen, if installed.
7. Install J 45268-4 to the A/C compressor suction hose.
8. Install J 45268-5 to the A/C compressor discharge hose.
Fig 1: A/C Filter & Check Valve
Courtesy of GENERAL MOTORS CORP.
9. Forward flow refrigerant flushing is recommended for contaminated refrigerant or PAG oil.

   Perform the following procedure:

   IMPORTANT: The filter inside the J 45268-1 is serviceable. Remove and discard the check valve from the filter.
   1. Service the filter with ACDelco P/N GF 470, before each flush.

      Connect the J 45268-1 flush filter to the suction port of the J 45268-4 flush adapter.

   2. Connect the blue hose from the J 43600  to the J 45268-1 flush filter adapter. See Special Tools .
   3. Connect the red hose from the J 43600  to the J 45268-5 flush adapter. See Special Tools .
10. Reverse flow refrigerant flushing is recommended for desiccant bag failure. Perform the following procedure and replace the accumulator when the flush procedure is complete.
    IMPORTANT: The filter inside the J 45268-1 is serviceable. Remove and discard the check valve from the filter.
    1. Service the filter with AC P/N GF 470, before each flush. Connect the J 45268-1 flush filter to the discharge port of the J 45268-5 flush adapter.
    2. Connect the blue hose from the J 43600  to the J 45268-1 flush filter adapter. See Special Tools .
    3. Connect the red hose from the J 43600  to the suction port of the J 45268-4 flush adapter. See Special Tools .
    IMPORTANT: Close the valve on the external refrigerant tank, before starting the flush process.
    4. Flush the front A/C system. Follow the instructions supplied with the J 43600  . See Special Tools .
11. Remove the J 45268-4 from the A/C compressor suction hose.
12. Remove the J 45268-5 from the A/C compressor discharge hose.
IMPORTANT: Flushing will remove all the PAG oil from the A/C system.
The A/C system must be replenished with the correct amount of PAG oil.
13. If the removed A/C compressor is being reinstalled, perform the following procedure:
    • Drain the PAG oil from the A/C compressor.
    • Rotate the compressor input shaft to assist in draining the PAG oil from the A/C compressor.
    • Add the total system capacity of PAG oil to the A/C compressor. Refer to Refrigerant System Specifications (Non-HP2)  .
14. If you will replace the A/C compressor after flushing the system, perform the following procedure:
    1. Determine if the new service compressor is shipped with PAG oil. Refer to the Refrigerant System Specifications (Non-HP2)  .
    2. If the service compressor is shipped with PAG oil, DO NOT drain the new PAG oil from the compressor.
    3. Deduct the amount of PAG oil shipped with the service compressor from the amount of PAG oil listed in the capacities table. Refer to Refrigerant System Specifications (Non-HP2)  .
    4. Add the calculated amount to the compressor, as needed.
IMPORTANT: Flushing will remove the fluorescent leak detection dye from the A/C system.
15. Add one bottle of J 41447  directly to the A/C compressor. See Special Tools .
16. Install the A/C compressor. Refer to Air Conditioning Compressor Replacement (LLY/LMM)  or Air Conditioning Compressor Replacement (LU3)  or Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)  or Air Conditioning Compressor Replacement (HP2) .
17. Install a new orifice tube. Refer to Expansion (Orifice) Tube Replacement .
18. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non-HP2)  or Refrigerant Recovery and Recharging (HP2) .
19. Leak test the fittings using J 42220  .