hvac
AC Compressor
for 2018 Ford F-150 3.5L V6 EcoBoost · RWD
Difficulty
Advanced
Time
3.0 h
Tools
10
Steps
14
This procedure covers the removal and replacement of the AC compressor on a 2015-2020 Ford F-150 with the 3.5L EcoBoost V6 engine, including refrigerant recovery, component removal, and system recharge.
Warnings
⚠️AC system is under high pressure. Refrigerant must be professionally recovered before opening any AC lines. Improper release is illegal and can cause severe frostbite injury.
⚠️PAG oil is hygroscopic and absorbs moisture rapidly. Keep all AC components capped until final assembly and minimize exposure to air.
⚠Ensure engine is completely cool before beginning work. The compressor is located near hot engine components.
⚠New compressors often come pre-filled with oil. Drain and measure oil from old compressor, then adjust new compressor oil to match (typically 4-6 oz total).
ℹ️This job requires EPA 609 certification for refrigerant handling in most jurisdictions. Professional AC recovery and recharge equipment is required.
Tools required
AC refrigerant recovery machineEssential
Torque wrench (5-50 Nm)Essential
Ratchet and socket set (metric)Essential
Crowfoot wrench set (for line fittings)Essential
Serpentine belt toolEssential
AC vacuum pumpEssential
AC manifold gauge setEssential
Floor jack and jack standsEssential
Thread sealant for AC fittings
UV dye kit
Parts
- AC Compressor assembly × 1 — Use OEM specification or quality aftermarket
- AC compressor O-ring kit × 1 — Use OEM specification
- PAG 46 compressor oil × 1 — Motorcraft YN-12-C or equivalent
- Serpentine belt × 1 — Replace if worn or contaminated with oil
- R-134a refrigerant × 1 — Approximately 1.75 lbs total system capacity
Preparation
- Park vehicle on level surface and engage parking brake
- Allow engine to cool completely for at least 2 hours
- Disconnect negative battery cable and isolate from terminal
- Using certified AC recovery equipment, fully recover refrigerant from the system and record amount recovered
- Raise front of vehicle and support securely on jack stands
- Remove engine splash shield and lower air deflectors for access
- Document or photograph serpentine belt routing before removal
Procedure
- 1Remove serpentine beltUsing serpentine belt tool, rotate tensioner clockwise to release tension. Remove belt from all pulleys including AC compressor pulley. Inspect belt for oil contamination or damage and replace if necessary.
- 2Disconnect compressor electrical connectorLocate the AC compressor clutch electrical connector on the front of the compressor. Press the release tab and disconnect the connector. Remove the connector bolt if equipped and set aside.Torque specClutch Connector Bolt8 Nm (6 lb-ft)
- 3Disconnect AC discharge lineUsing appropriate crowfoot wrench, loosen and remove the discharge line (high pressure side) fitting from the top rear of the compressor. Immediately cap both the line and compressor port to prevent moisture and contamination entry. Remove and discard the O-ring from the line.⚠Even after recovery, residual refrigerant or pressure may remain. Work slowly and wear safety glasses.Torque specAC Line Fittings20 Nm (15 lb-ft)
- 4Disconnect AC suction lineRemove the suction line (low pressure side) fitting from the compressor, typically located on the lower portion. Use crowfoot wrench to avoid rounding the fitting. Immediately cap both openings. Remove and discard the O-ring.Torque specAC Line Fittings20 Nm (15 lb-ft)
- 5Remove compressor mounting boltsLocate the three compressor mounting bolts securing the compressor to the engine bracket. The 3.5L EcoBoost has bolts accessible from the front and side. Remove all mounting bolts and support the compressor weight as the final bolt is removed.
- 6Remove AC compressorCarefully maneuver the compressor out of the engine bay, working it past the frame rail and other components. The compressor may need to be tilted and rotated to clear obstructions. Lower it through the bottom of the vehicle if necessary.
- 7Drain and measure compressor oilDrain oil from the old compressor into a clean graduated container by rotating it and draining from both ports. Measure and record the amount of oil recovered. This determines how much oil to add to the new compressor. Inspect oil for metal particles or contamination.⚠If metal particles are present in the oil, the AC system may be contaminated and require full system flush before installing new compressor.
- 8Prepare new compressorRemove shipping caps from new compressor. Drain pre-filled oil and measure. Add correct amount of fresh PAG 46 oil to match what was removed from old compressor (typically 4-6 oz total). Rotate compressor pulley 10-15 times to distribute oil internally.
- 9Install new compressorManeuver new compressor into position in the engine bay, reversing removal path. Align compressor with mounting bracket and start all three mounting bolts by hand before tightening any. Ensure compressor is properly seated on bracket.
- 10Torque compressor mounting boltsUsing torque wrench, tighten all three compressor mounting bolts in a star pattern to ensure even seating. Torque to specification.
- 11Install new O-rings and connect AC linesInstall new O-rings onto both AC line fittings, coating them lightly with fresh PAG oil. Remove caps from compressor ports. Connect suction line first, then discharge line. Hand-tighten fittings, then use crowfoot wrench and torque wrench to torque to specification. Do not overtighten as this can damage O-rings.Torque specAC Line Fittings20 Nm (15 lb-ft)
- 12Reconnect electrical connectorReconnect the AC compressor clutch electrical connector, ensuring it clicks into place. Install connector bolt if equipped and torque to specification.Torque specClutch Connector Bolt8 Nm (6 lb-ft)
- 13Install serpentine beltRoute new or existing serpentine belt around all pulleys according to routing diagram. Use belt tool to rotate tensioner and slip belt onto final pulley. Release tensioner slowly and verify belt is properly seated in all pulley grooves.
- 14Evacuate and recharge AC systemReconnect battery. Using AC vacuum pump, evacuate the system to at least 29 inches Hg vacuum for minimum 45 minutes to remove all moisture. System should hold vacuum for 30 minutes without loss. Recharge system with R-134a refrigerant to specification (approximately 1.75 lbs total). Add UV dye if desired for future leak detection.ℹ️AC system must be evacuated to remove all moisture introduced during compressor replacement. Moisture will damage new compressor and reduce system performance.
Reassembly
- Reinstall engine splash shield and lower air deflectors
- Lower vehicle from jack stands
- Verify all tools and materials are removed from engine bay
- Double-check all electrical connections and line fittings for security
Verification
- Start engine and set AC to maximum cold and high fan speed
- Verify AC compressor clutch engages and disengages properly with AC switch
- Check for abnormal noises from compressor during operation
- Monitor AC manifold gauges: low side should be 25-45 psi, high side 200-250 psi at idle (ambient temp dependent)
- Verify cold air output from vents reaches appropriate temperature (typically 38-42°F at vent)
- Inspect all AC line connections for signs of refrigerant leaks using leak detector or soap solution
- Allow system to run for 10-15 minutes and recheck pressures and outlet temperature
- Verify no oil leaks from compressor or line fittings after test run