Replace Your Car's AC Thermal Expansion Valve or Orifice Tube


Your car or truck's AC system is under extreme pressure and the thermal expansion valve or orifice tube monitors the amount of pressure and the temperature of your A/C system. It calculates the precise amount of refrigerant that can safely go into the evaporator. A failing expansion valve or orifice tube often causes a vehicle's air conditioner to blow hot air.

Replace or Repair

  • Expansion Valves: Too much refrigerant causes your evaporator to get too cold whereas too little refrigerant would result in inadequate cooling. The expansion valve is a complex valve that regulates refrigerant flow. This process of metering the refrigerant adjusts the flow according to the temperature of the refrigerant in the evaporator coil. Talk to one of the pro mechanics at Trowell & Turner Automotive, as this part can be replaced on its own and does not require the entire replacement of the AC assembly.
  • Orifice Tubes: Unlike the expansion valve, the orifice tube is a simple fixed device with no moving parts. It therefore cannot vary the flow of refrigerant into the evaporator, but rather causes a permanent restriction in the system. However, like the expansion valve the orifice tube regulates refrigerant flow through the system and filters debris which may come through in its screen. Often fixing a "bad orifice tube" requires replacing the entire evaporator assembly.


Reviews

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Honest and Great Mechanics. Took my Lexus to 3 places to diagnose a noise. It was mis-diagnosed at all but TT. And even before they got it right they did replace a part that did not fix the issue and would not let me pay so I brought it back and they nailed it. These guys are my only mechanics now.

, 01/10/2026

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I've been bringing our cars to Trowell and Turner for years, and these guys never let me down. They are honest, reliable, and fast - you won't find that kind of service and quality at other places in Dallas.

, 10/30/2025

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I’m glad my car issue occurred near them. It’s hard finding a honest car shop to trust when you’re in desperation. You just got a loyal customer in me. Thank you for the first class service and fair pricing!

, 09/23/2025

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