Expansion Valve Expansion valve regulates refrigerant temperature in evaporator. Expansion valve is Silver in color and located on right side of engine firewall. Test it as follows:EXPANSION VALVE 1. Ensure work area ambient temperature is 70-85 F (21-27 C). Install manifold gauge set. Verify A/C system is fully charged. Close all doors, windows and vents. Turn A/C on. Set controls to full heat, floor mode and high speed settings. 2. Start and run engine at normal idle (1000 RPM). Allow engine to reach normal operating temperature. Allow passenger compartment to heat up. This creates maximum refrigerant flow into evaporator. 3. Note manifold gauge readings. High side (discharge) pressure should be 140-240 psi (9.8-16.9 kg/cm 2 ). Low side (suction) pressure should be 20-30 psi (1.4-2.1 kg/cm 2 ). If readings are not correct, replace expansion valve. If readings are correct, go to next step. 4. Using CO2, freeze head of expansion valve. DO NOT use refrigerant to freeze expansion valve. Low side (suction) gauge pressure reading should drop by 10 psi (0.7 kg/cm 2 ). If low side (suction) gauge pressure does not drop by 10 psi, replace expansion valve. If low side (suction) gauge pressure is correct, go to next step. 5. Allow expansion valve to thaw. Low side (suction) gauge pressure reading should stabilize at 20-30 psi (1.4-2.1 kg/cm 2 ). If reading fails to stabilize, replace expansion valve. Remove manifold gauge set. To remove it, you need to remove the top alt brackett, negative battery cable, field wire from alt, push alt out of the way and remove it. Sorry I couldnt find a picture.
Sunday, June 28th, 2009 AT 8:04 AM