This procedure covers the removal and replacement of the AC expansion valve (TXV) on a 2021-2024 Ford F-150 with the 3.5L EcoBoost V6 engine, including refrigerant recovery, system evacuation, and recharge.

Warnings

Tools required

Parts

• AC Expansion Valve (TXV) × 1 — Use OEM specification for R-134a or R-1234yf system
• AC line O-ring kit × 1 — Includes various sizes for AC fittings
• PAG oil (PAG-46 for R-134a or PAG-ND-12 for R-1234yf) × 1 — Match oil type to refrigerant system
• AC system refrigerant × 1 — R-134a or R-1234yf (verify system label)

Fluids

• PAG oil (system-specific) — 0.25 qt

Preparation

1. Verify the refrigerant type (R-134a or R-1234yf) from the AC system label under the hood
2. Park vehicle on level ground, engage parking brake, and place wheel chocks
3. Allow engine to cool completely if recently operated
4. Disconnect negative battery cable and wait 2 minutes before proceeding
5. Ensure AC recovery machine is compatible with vehicle's refrigerant type and properly maintained
6. Gather all required tools, new expansion valve, O-rings, and correct PAG oil type

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to the high and low side service ports. Follow machine manufacturer instructions to completely recover all refrigerant from the system. Record the amount of oil recovered from the machine's collection bottle to determine replacement quantity. Once recovery is complete and system shows 0 PSI, disconnect recovery machine.
   ⚠️Only EPA-certified technicians may recover AC refrigerant. Venting refrigerant to atmosphere is illegal and environmentally harmful.
2. 2

   Remove lower passenger dash panel
   Open passenger door. Locate and remove the lower dash insulator panel fasteners (combination of screws and push-pin clips). Carefully pull the lower panel away from the dash to release remaining clips. Disconnect any electrical connectors for lights or sensors. Set panel aside.
3. 3

   Remove glove box assembly
   Open glove box and remove contents. Squeeze sides of glove box inward to release stop arms from dash frame. Lower glove box down and disconnect any damper straps. Remove the glove box mounting screws (typically 4-6 screws) and remove glove box assembly completely. This provides access to the evaporator housing area.
4. 4

   Access evaporator case cover
   Locate the evaporator case on the passenger side of the HVAC unit behind where the glove box was mounted. Identify the access cover that provides entry to the expansion valve area. Disconnect any wire harnesses or clips attached to the cover. Note the routing of wires and hoses for reassembly.
5. 5

   Remove evaporator case cover
   Remove the evaporator case access cover screws. On some models, this may also require removing duct clips or additional fasteners. Carefully pull the cover away from the case, being mindful of any remaining clips or seal material. Inspect the seal/gasket on the cover and replace if damaged.
   Torque spec

   Cover Screws12 Nm (9 lb-ft)

   Duct Clips3 Nm (2 lb-ft)
6. 6

   Locate and access expansion valve
   With the cover removed, locate the expansion valve (TXV) at the evaporator inlet. The valve has two refrigerant line connections and may have a capillary tube sensor bulb attached to the evaporator outlet. Take photos of the orientation and routing for reference during installation. Note the position of any insulation or foam seals.
7. 7

   Disconnect refrigerant lines from expansion valve
   Using appropriate AC line disconnect tools, carefully disconnect the inlet and outlet refrigerant lines from the expansion valve. Place caps or plugs over the open line ends immediately to prevent moisture and debris entry. Inspect the line fittings and O-rings for damage. Remove and discard old O-rings from the line fittings.
   ⚠Even after recovery, residual refrigerant or oil may escape. Wear safety glasses and have shop towels ready.
8. 8

   Remove expansion valve
   If the expansion valve has a capillary tube with sensing bulb attached to the evaporator, carefully detach the bulb from its mounting location. Remove the expansion valve mounting fasteners. Carefully extract the expansion valve from the evaporator case, being mindful not to damage the evaporator fins or tubes. Remove any old O-rings or seals from the valve mounting area.
   Torque spec

   Expansion Valve10 Nm (7 lb-ft)
9. 9

   Prepare new expansion valve
   Unpack the new expansion valve and verify it matches the original part configuration. Install new O-rings onto the valve body connections, lubricating them lightly with the appropriate PAG oil (PAG-46 for R-134a or PAG-ND-12 for R-1234yf). Do not over-lubricate. If the valve has a sensing bulb, ensure the capillary tube is not kinked or damaged.
10. 10

    Install new expansion valve
    Position the new expansion valve into the evaporator case in the same orientation as the original. If equipped with a sensing bulb, route the capillary tube correctly and secure the bulb to the evaporator outlet tube in the factory location using the provided clamp or insulation. Install and torque the expansion valve mounting fasteners to specification.
    Torque spec

    Expansion Valve10 Nm (7 lb-ft)
11. 11

    Connect refrigerant lines
    Install new lubricated O-rings onto the refrigerant line fittings. Apply a small amount of appropriate PAG oil to the O-rings. Connect the inlet and outlet refrigerant lines to the new expansion valve, ensuring proper alignment. Torque the AC line fittings to specification. Verify connections are secure and properly seated.
    ℹ️Use only new O-rings and fresh PAG oil. Old or dry O-rings will cause system leaks.
    Torque spec

    AC Line Fittings20 Nm (15 lb-ft)
12. 12

    Reinstall evaporator case cover
    Inspect the evaporator case cover seal or gasket and replace if necessary. Position any insulation or foam seals back in their original locations. Install the evaporator case cover, ensuring all alignment tabs are properly engaged. Install and torque cover screws to specification. Reconnect any duct clips to proper torque.
    Torque spec

    Cover Screws12 Nm (9 lb-ft)

    Duct Clips3 Nm (2 lb-ft)
13. 13

    Reinstall interior components
    Reconnect any wire harnesses or connectors that were disconnected. Reinstall the glove box assembly, securing with mounting screws. Reconnect glove box damper straps and ensure stop arms engage properly. Install the lower dash insulator panel, ensuring all clips and fasteners are properly secured. Reconnect any electrical connectors.
14. 14

    Evacuate AC system
    Reconnect the negative battery cable. Connect AC evacuation equipment to the service ports. Pull a vacuum on the system for a minimum of 45 minutes, or until the system reaches and holds 29+ inches of mercury vacuum. After evacuation, close valves and monitor vacuum gauge for 10 minutes. If vacuum holds steady, system is leak-free and ready for charging.
    ⚠If vacuum does not hold, there is a leak. Re-inspect all connections and repeat evacuation test before charging with refrigerant.
15. 15

    Recharge AC system and add oil
    Calculate the correct PAG oil quantity to add: replace the amount recovered plus 1 ounce for the new expansion valve. Add the appropriate PAG oil to the system through the low side port before charging refrigerant. Charge the system with the correct type and amount of refrigerant per the underhood AC specification label (typically 1.5-2.1 lbs depending on configuration). Follow charging machine instructions for proper procedure.

Reassembly

1. Verify all interior panels, glove box, and dash components are properly secured with no loose fasteners or rattles
2. Ensure all electrical connectors are properly engaged and locked
3. Check that all AC line connections are torqued to specification and show no signs of refrigerant leakage
4. Confirm evaporator case cover is properly sealed with no air gaps

Verification

• Start the engine and turn AC to maximum cool with fan on high. Allow system to run for 5 minutes
• Verify cold air is blowing from all vents at approximately 40-50°F with ambient temperature above 70°F
• Check AC pressures with manifold gauges: low side should be 25-40 PSI and high side 150-250 PSI at idle (varies with ambient temperature)
• Inspect all AC line connections for signs of refrigerant leakage using electronic leak detector or soap solution
• Listen for abnormal noises from the evaporator area or compressor cycling
• Verify compressor clutch engages smoothly and cycles appropriately based on temperature demands
• Test AC performance at various fan speeds and temperature settings to ensure proper operation
• Scan for any HVAC or AC-related diagnostic trouble codes using a scan tool

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