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Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different car >> Section 55 (Heating, Ventilation, And Air Conditioning System) >> Repair Instructions >> Flushing

Repair Instructions: Flushing

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required

IMPORTANT:

Flushing is not intended to remove metal from the A/C system.

Flushing is intended to remove the following:

    IMPORTANT:

    Warmer engine or ambient temperature decreases the refrigerant recovery time during the A/C flush procedure.

  1. Recover the refrigerant. Refrigerant Recovery and Recharging .
  2. Remove the orifice tube. Expansion (Orifice) Tube Replacement .
  3. Connect the A/C lines with the orifice tube removed.
  4. Remove the A/C compressor. Air Conditioning Compressor Replacement (LWN) , or Air Conditioning Compressor Replacement (LV1) , or Air Conditioning Compressor Replacement (L96, LC8) .
  5. Inspect the end of the suction hose for a suction screen.
  6. Remove the suction screen, if installed.
  7. Install the J 45268-3 to the A/C compressor hose assembly.
  8. GM787687Courtesy of GENERAL MOTORS COMPANY

    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 45268-3 flush adapter.

    2. Connect the blue hose from the J 43600  center to the J 45268-1 flush filter adapter.
    3. Connect the red hose from the J 43600  center to the J 45268-3 flush adapter.
  9. 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 ACDelco P/N GF 470, before each flush.

      Connect the J 45268-1 flush filter to the discharge port of the J 45268-3 flush adapter.

    2. Connect the blue hose from the J 43600  center to the J 45268-1 flush filter adapter.
    3. Connect the red hose from the J 43600  center to the suction port of the J 45268-3 flush adapter.
  10. Flush the front A/C system. Follow the instructions supplied with the J 43600  center.

    Close the valve on the external refrigerant tank, before starting the flush process.

    11. IMPORTANT:

    Flush the front A/C system before flushing the auxiliary A/C system.

  11. If the vehicle is equipped with rear A/C, flush the auxiliary A/C system separately.
  12. GM756678Courtesy of GENERAL MOTORS COMPANY

    Cut the orifice tube frame and screen, enough to access the end of the orifice tube. Pinch off the orifice tube.

  13. GM756680Courtesy of GENERAL MOTORS COMPANY
    IMPORTANT:

    Pinch off the orifice tube in order to prevent refrigerant flow to the front system during the auxiliary system flush.

    Install the pinched orifice tube. Expansion (Orifice) Tube Replacement .

  14. Remove the auxiliary thermostatic expansion valve (TXV). Auxiliary Air Conditioning Evaporator Thermal Expansion Valve Replacement .
  15. Install the J 45268-104.
    16. IMPORTANT:

    The auxiliary evaporator core can be flushed without totally reassembling into the auxiliary HVAC module.

  16. Install the auxiliary evaporator core to the A/C lines.
  17. Raise the vehicle. Lifting and Jacking the Vehicle .
  18. Connect the auxiliary A/C lines to the auxiliary evaporator core.
  19. Lower the vehicle.
  20. Flush the auxiliary A/C system. Follow the instructions supplied with the J 43600  center.
  21. Raise the vehicle. Lifting and Jacking the Vehicle .
  22. Remove the auxiliary A/C lines from the auxiliary evaporator core.
  23. Lower the vehicle.
  24. Remove the J 45268-104.
  25. Inspect the TXV for debris.

    Clean or replace, as needed.

  26. Install the auxiliary TXV. Auxiliary Air Conditioning Evaporator Thermal Expansion Valve Replacement .
  27. Remove the J 45268-3 from the A/C compressor hose assembly.
    28. 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.

  28. Drain the PAG oil from the A/C compressor. Rotate the compressor input shaft to assist in draining the PAG oil from the compressor.
  29. Add back the total system capacity of PAG oil to the A/C compressor. Approximate Fluid Capacities .
  30. If you will be replacing the A/C compressor after flushing the system, perform the following procedure:
    • Determine if the new service compressor is shipped with PAG oil. Approximate Fluid Capacities .
    • If the service compressor is shipped with PAG oil, DO NOT drain the new PAG oil from the compressor.
    • Deduct the amount of PAG oil shipped with the service compressor from the amount of PAG oil listed in the capacities table. Approximate Fluid Capacities .
    • Add the calculated amount to the compressor, as needed.
    31. IMPORTANT:

    Flushing will remove the fluorescent leak detection dye from the A/C system.

  31. Add one bottle of J 41447  dye.
  32. Install the A/C compressor. Air Conditioning Compressor Replacement (LWN) , or Air Conditioning Compressor Replacement (LV1) , or Air Conditioning Compressor Replacement (L96, LC8) .
  33. Install a new orifice tube. Expansion (Orifice) Tube Replacement .
  34. Evacuate and recharge the A/C system. Approximate Fluid Capacities .
  35. Leak test the fittings using the J 42220  lamp.
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