Testing and Inspection of Front Expansion Valve for Durango 2WD V8-57L Hybrid (2009)
Expansion Valve: Testing and Inspection
Front
A/C EXPANSION VALVE
WARNING: Refer to the applicable warnings and cautions for this system before performing the following operation See: Service
Precautions/Warning and See: Service Precautions/Caution . Failure to follow the warnings and cautions may result in possible
serious or fatal injury.
NOTE: Liquid CO2 is required to test the A/C expansion valve. This material is available from most welding supply facilities. Liquid CO2 is
also available from companies which service and sell fire extinguishers. DO NOT use R-134a or R-12 refrigerant for this test.
When testing the A/C expansion valve, the work area and the vehicle temperature must be 21° to 27° C (70° to 85° F). To test the expansion valve:
NOTE: The A/C expansion valve should only be tested following testing of the A/C compressor.
1. Verify the A/C compressor is operating to design standards See: Testing and Inspection/Component Tests and General Diagnostics.
2. Connect a charging station or manifold gauge set to the refrigerant system service ports. Verify the refrigerant charge level.
3. Close all doors and windows.
4. Set the A/C-heater controls to the following positions:
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temperature control to full warm
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mode control to floor
-
blower motor control to high speed
5. Start the engine and allow it to idle. After the engine has reached normal operating temperature, allow the passenger compartment to heat up. This
will create the need for maximum refrigerant flow into the A/C evaporator.
6. With passenger compartment heated up, set the A/C-heater controls to the following positions:
-
A/C compressor engaged
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temperature control to full cold
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mode control to panel
-
blower motor control to high speed
7. With the correct refrigerant charge level, the high pressure gauge should read approximately 930 kPa to 1725 kPa (135 psi to 250 psi) and the low
pressure gauge should read approximately 175 kPa to 380 kPa (25 psi to 55 psi). If OK, go to 8. If not OK, replace the faulty A/C expansion
valve.
WARNING:
Protect the skin and eyes from exposure to liquid CO2 or possible serious injury can result.
8. If the low pressure gauge reads within the specified range, freeze the A/C expansion valve for 30 seconds using liquid CO2 or another suitable
super-cold material. Do not spray R-134a or R-12 refrigerant on the A/C expansion valve for this test. The low pressure gauge reading should
drop by 70 kPa (10 psi). If OK, go to 9 If not OK, replace the faulty A/C expansion valve.
9. Allow the expansion valve control head to thaw. The low pressure gauge reading should stabilize at approximately 175 kPa to 380 kPa (25 psi to
55 psi). If not OK, replace the faulty A/C expansion valve.
