Replace the AC expansion valve (TXV) on a 2014 Ram 2500 with 6.7L Cummins diesel engine, requiring recovery and recharge of the AC refrigerant system.

Warnings

Tools required

Parts

• AC Expansion Valve (TXV) × 1 — Use OEM specification for 6.7L Cummins
• AC O-ring kit × 1 — Use OEM AC line O-ring set
• PAG oil for AC system × 1 — PAG 46 or as specified by compressor
• R-134a refrigerant × 1 — Approximately 3.5 lbs for system

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine to cool completely if recently operated
3. Gather all necessary AC service equipment and ensure recovery machine is functioning properly
4. Verify replacement expansion valve matches OEM specifications for 6.7L Cummins application
5. Prepare clean workspace and containers for old O-rings and components

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to the service ports on the high and low side of the AC system. Follow recovery machine instructions to completely evacuate all refrigerant from the system. Record the amount of refrigerant recovered for recharge reference. Allow system to equalize to atmospheric pressure.
2. 2

   Access expansion valve location
   The expansion valve on the 6.7L Cummins 2500 is located at the firewall near the evaporator inlet. Remove the engine cover if equipped. Remove any air intake components or cowl panels obstructing access to the firewall area where AC lines enter the cabin. On 4WD models, you may need to remove portions of the underhood insulation for better access.
3. 3

   Disconnect battery negative terminal
   Disconnect the negative battery terminal to prevent any electrical issues while working near AC components and sensors. Move cable away from battery post to prevent accidental reconnection.
4. 4

   Disconnect AC lines from expansion valve
   Locate the inlet and outlet AC line connections at the expansion valve. Using appropriate wrenches, carefully loosen and disconnect both AC line fittings from the expansion valve body. Cap or plug the open lines immediately to prevent contamination and moisture entry. Inspect the old O-rings for damage or deterioration.
   ⚠Residual refrigerant or oil may leak when lines are disconnected. Have shop towels ready.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
5. 5

   Remove expansion valve mounting
   Remove the mounting hardware securing the expansion valve to its bracket or evaporator housing. The valve may be held by bolts or screws depending on the specific configuration. Carefully extract the expansion valve assembly, noting the orientation and any sensor connections that may need disconnection.
   Torque spec

   Mounting Bolts37 Nm (27 lb-ft)

   Cover Screws15 Nm (11 lb-ft)
6. 6

   Inspect and clean mounting location
   Thoroughly inspect the mounting surface and surrounding area for any signs of oil leakage, corrosion, or debris. Clean the mounting surface and AC line connection points with a lint-free cloth. Check that the evaporator connections are clean and undamaged. If a screen filter is present at the expansion valve inlet, inspect it for debris.
7. 7

   Prepare new expansion valve
   Remove the new expansion valve from packaging. Verify it matches the original valve orientation and connection points. Lightly coat new O-rings with fresh PAG oil (approximately 1-2 drops per O-ring). Install new O-rings onto the expansion valve inlet and outlet ports, ensuring they seat properly in their grooves.
   ℹ️Use only PAG oil compatible with R-134a systems. Do not use mineral oil or other lubricants.
8. 8

   Install new expansion valve
   Position the new expansion valve in the correct orientation matching the original installation. Install and hand-tighten the mounting hardware. Torque the expansion valve mounting bolts to specification using a calibrated torque wrench.
   Torque spec

   Expansion Valve10 Nm (7 lb-ft)

   Mounting Bolts37 Nm (27 lb-ft)
9. 9

   Reconnect AC lines
   Remove caps or plugs from AC lines. Inspect line fittings and install new O-rings lubricated with PAG oil on both the inlet and outlet line connections. Carefully thread the AC line fittings onto the new expansion valve by hand to ensure proper engagement. Once hand-tight, torque the fittings to specification using a backup wrench on the valve body to prevent rotation.
   ⚠Cross-threading AC fittings will damage the expansion valve. Ensure threads engage smoothly before applying torque.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
10. 10

    Vacuum test AC system
    Connect AC vacuum pump to system service ports. Pull a deep vacuum on the AC system for a minimum of 45 minutes to remove all moisture and air. The system should achieve and hold at least 29 inches of mercury vacuum. After vacuum period, close valves and monitor gauge for 15 minutes to verify system holds vacuum, confirming no leaks are present.
    ℹ️If system will not hold vacuum, there is a leak that must be found and repaired before charging.
11. 11

    Add refrigerant oil
    Add the appropriate amount of fresh PAG oil to compensate for oil lost during recovery and component replacement. Typically add 2-3 ounces for expansion valve replacement. Consult service information for exact oil capacity if system was completely empty.
12. 12

    Recharge AC system
    Using AC charging equipment, recharge the system with R-134a refrigerant to the factory specified amount (approximately 3.5 lbs total system capacity, adjust based on amount recovered). Charge through the low-side port with engine running and AC on MAX. Monitor pressures on manifold gauges to ensure proper charging. Do not overcharge the system.
13. 13

    Leak test system
    With system fully charged, use electronic leak detector to check all connections including the new expansion valve inlet and outlet fittings. Check for any signs of refrigerant oil weeping. If any leaks are detected, recover refrigerant, repair leak, and repeat vacuum and recharge process.
14. 14

    Reassemble and reconnect
    Reconnect the battery negative terminal. Reinstall all removed components including engine covers, cowl panels, air intake components, and insulation in reverse order of removal. Ensure all fasteners are properly secured and no tools or parts are left in engine bay.

Reassembly

1. Verify all AC line connections are properly torqued and free from oil residue indicating leaks
2. Ensure all cowl panels and engine covers are reinstalled and secured
3. Double-check that no tools or shop towels were left in the engine compartment
4. Confirm battery is reconnected and terminal is clean and tight

Verification

• Start engine and turn AC to MAX setting with blower on high
• Allow system to run for 10 minutes and verify cold air is being produced at vents
• Check that AC compressor is cycling properly and not short-cycling
• Monitor AC pressures with manifold gauges: low side should be 25-35 PSI and high side 200-250 PSI at ambient temperature around 75-80°F
• Verify no unusual noises from AC system operation
• Perform final visual inspection of all AC connections for any signs of leakage
• Test AC performance at idle and at 2000 RPM to confirm proper operation under various conditions
• Confirm vent temperature is achieving 35-45°F at center vents with ambient temperature around 75-80°F

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