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Home >> Chevy Truck >> 2010 >> Express 3500 V8-6.6L DSL Turbo >> Repair and Diagnosis >> Heating and Air Conditioning >> Service and Repair >> Flushing

Flushing




Flushing

Tools Required
* J 43600 Air Conditioning Service Center
* J 45268 Flush Adapter Kit
* J 41447 Leak Detection Dye
* J 42220 Universal 12V Leak Detection Lamp

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


Flushing is intended to remove the following:

* 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 (Refrigerant Recovery and Recharging).
2. Remove the orifice tube. Refer to Expansion (Orifice) Tube Replacement (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 (4.3L) ().
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. 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 AC Delco 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 to the J 45268-1 flush filter adapter.
3. Connect the red hose from the J 43600 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 AC Delco 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 to the J 45268-1 flush filter adapter.
3. Connect the red hose from the J 43600 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.
Close the valve on the external refrigerant tank, before starting the flush process.

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





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


13. Install the pinched orifice tube. Refer to Expansion (Orifice) Tube Replacement (Expansion (Orifice) Tube Replacement).
14. Remove the auxiliary thermostatic expansion valve (TXV). Refer to Auxiliary Air Conditioning Evaporator Thermal Expansion Valve Replacement (Auxiliary Air Conditioning Evaporator Thermal Expansion Valve Replacement).
15. Install the J 45268-104.

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. Refer to Lifting and Jacking the Vehicle (Service and Repair).
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.
21. Raise the vehicle. Refer to Lifting and Jacking the Vehicle (Service and Repair).
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. Refer to Auxiliary Air Conditioning Evaporator Thermal Expansion Valve Replacement (Auxiliary Air Conditioning Evaporator Thermal Expansion Valve Replacement).
27. Remove the J 45268-3 from the A/C compressor hose assembly.

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. Refer to Refrigerant System Specifications ([1][2]Capacity Specifications).
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. Refer to Refrigerant System Specifications ([1][2]Capacity Specifications).
* 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. Refer to Refrigerant System Specifications ([1][2]Capacity Specifications).
* Add the calculated amount to the compressor, as needed.

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


31. Add one bottle of J 41447.
32. Install the A/C compressor. Refer to Air Conditioning Compressor Replacement (4.3L) ().
33. Install a new orifice tube. Refer to Expansion (Orifice) Tube Replacement (Expansion (Orifice) Tube Replacement).
34. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Refrigerant Recovery and Recharging).
35. Leak test the fittings using the J 42220.

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