This procedure covers removal and replacement of the AC compressor on a 2014 Ram 2500 with 6.7L Cummins diesel engine, including refrigerant recovery, compressor replacement, and system recharge.

Warnings

Tools required

Parts

• AC Compressor × 1 — Use OEM specification
• AC line O-rings × 1 — Use OEM specification
• PAG oil (for compressor) × 1 — Use OEM specification
• R-134a refrigerant × 1 — Use OEM specification
• Serpentine belt (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely if recently operated
3. Disconnect negative battery cable to prevent accidental compressor clutch engagement
4. Verify AC refrigerant recovery machine is functioning and properly calibrated
5. Have replacement compressor, O-rings, and PAG oil ready before beginning

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to service ports (low and high side). Follow machine instructions to completely recover all refrigerant from the system. Record the amount of refrigerant and oil recovered for recharge reference. Ensure system pressure reaches 0 PSI before proceeding.
2. 2

   Remove serpentine belt
   Locate the automatic belt tensioner on the front of the engine. Use a socket or wrench to rotate the tensioner clockwise to release tension. Remove the serpentine belt from all pulleys, noting the routing path. Inspect belt for wear or damage and replace if necessary.
3. 3

   Disconnect compressor electrical connector
   Locate the electrical connector on the AC compressor clutch. Press the release tab and disconnect the connector. If connector has a retaining bolt, remove it first. Move wiring harness aside to prevent damage during compressor removal.
   Torque spec

   Clutch Connector Bolt8 Nm (6 lb-ft)
4. 4

   Disconnect AC line fittings
   Using appropriate wrenches, disconnect the suction line (low pressure) and discharge line (high pressure) from the compressor. Support the lines while loosening to prevent stress on connections. Cap all open ports immediately to prevent moisture and contamination from entering the system. Remove and discard old O-rings.
   ⚠Even after recovery, residual refrigerant or oil may be present in lines. Have shop towels ready.
   Torque spec

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

   Remove AC compressor mounting bolts
   Locate the compressor mounting bolts securing the compressor to the engine bracket. On the 6.7L Cummins, the compressor is mounted low on the driver side of the engine. Remove all mounting bolts while supporting the compressor weight. Note bolt locations if lengths differ.
6. 6

   Remove AC compressor
   Carefully maneuver the compressor out of the engine bay. The 6.7L Cummins installation is tight; you may need to angle the compressor to clear surrounding components. Avoid damaging nearby hoses, wiring, or components during removal.
7. 7

   Prepare new compressor
   Remove shipping caps from new compressor. Verify the compressor contains the correct amount of PAG oil per manufacturer instructions (typically 6-8 oz for this application). If compressor is empty, add the appropriate amount of fresh PAG oil. Rotate compressor shaft by hand 10-15 times to distribute oil internally.
   ℹ️Subtract any oil recovered during refrigerant recovery from the total oil charge to avoid overfilling.
8. 8

   Install new compressor
   Position the new compressor into the mounting bracket, carefully maneuvering it into place. Align mounting holes with bracket. Start all mounting bolts by hand before tightening to ensure proper alignment.
9. 9

   Torque compressor mounting bolts
   Tighten the compressor mounting bolts in a cross pattern to ensure even seating. Torque all bolts to specification using a calibrated torque wrench. Verify compressor is securely mounted with no movement.
10. 10

    Install new O-rings and reconnect AC lines
    Install new O-rings on both AC line fittings. Lightly coat O-rings with clean PAG oil to aid installation and prevent damage. Connect the suction and discharge lines to the compressor, ensuring fittings seat completely. Tighten fittings to specification using a torque wrench and backup wrench to prevent line twisting.
    Torque spec

    AC Line Fittings20 Nm (15 lb-ft)
11. 11

    Reconnect electrical connector
    Reconnect the electrical connector to the compressor clutch. Ensure connector locks securely with an audible click. If applicable, install and torque the connector retaining bolt.
    Torque spec

    Clutch Connector Bolt8 Nm (6 lb-ft)
12. 12

    Reinstall serpentine belt
    Route the serpentine belt around all pulleys following the factory routing diagram (typically shown on a decal near the radiator). Rotate the belt tensioner clockwise and slip the belt onto the final pulley. Release tensioner slowly to apply tension. Verify belt is properly seated in all pulley grooves.
13. 13

    Evacuate AC system
    Connect vacuum pump to AC service ports. Evacuate the system to at least 29 inches of mercury (Hg) and hold for minimum 30-45 minutes. Monitor vacuum gauge for any pressure rise indicating a leak. If vacuum holds steady, system is ready for recharge.
    ℹ️Proper evacuation removes moisture and air which can damage the system and reduce cooling performance.
14. 14

    Recharge AC system
    Using AC manifold gauges and refrigerant scale, recharge the system with the correct amount of R-134a refrigerant per factory specifications (typically 38-42 oz for this vehicle). Charge through the low-side port with engine running and AC on max/recirculate. Monitor pressures throughout charging process.

Reassembly

1. Reconnect negative battery cable
2. Start engine and verify serpentine belt operation with no unusual noises
3. Verify AC compressor clutch engages when AC is turned on
4. Check all AC line connections for signs of refrigerant leaks using electronic leak detector or soap solution

Verification

• Turn AC system to maximum cooling and verify cold air from vents within 2-3 minutes
• Check AC system pressures with manifold gauges: low side should be 25-45 PSI, high side 200-275 PSI at idle with ambient temperature 70-80°F
• Verify compressor clutch cycles normally without excessive noise or vibration
• Inspect compressor mounting area for any refrigerant oil leaks after test drive
• Confirm no unusual noises from serpentine belt or compressor during operation
• Test AC performance during 15-minute drive cycle to ensure consistent cooling

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