Q: A/C starts cooling but then stops completely after a few miles. Used to hear the expansion valve operating but don't anymore.

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A/C starts working for a few miles then stops blowing cold air completely, seems like the expansion valve isn't working as don't hear the sound it used to make. The guages showed the head pressure kept going up but the low pressure stayed low.

My car has 23000 miles.
My car has an automatic transmission.

The problem sounds like the expansion valve is stuck in one position and not regulating refrigerant flow through the evaporator causing the pressures to be too high on the high side and too low on the low side. Have the thermostatic expansion valve replaced.

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