Replace the AC hose assembly on a 2021-2024 Ford F-150 3.5L EcoBoost, including refrigerant recovery, hose removal and installation, and system recharge.

Warnings

Tools required

Parts

• AC hose assembly × 1 — Use OEM specification for specific hose location
• AC line O-rings × 4 — Use OEM specification
• PAG 46 compressor oil × 1 — Motorcraft YN-12-C
• R-1234yf refrigerant × 1 — As required by system capacity

Fluids

• PAG 46 compressor oil — 0.25 qt

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery cable and wait 2 minutes for system discharge
4. Locate the AC hose assembly requiring replacement (suction line, discharge line, or liquid line)
5. Position vehicle on jack stands if hose is located underneath
6. Remove engine cover by pulling upward on clips
7. Remove any interfering air intake ducting or shrouding for access

Procedure

1. 1

   Recover refrigerant from AC system
   Connect AC recovery machine to high and low side service ports. Follow machine instructions to completely recover all R-1234yf refrigerant from the system. Record amount recovered for recharge reference. Verify system is at 0 psi before proceeding.
2. 2

   Remove interfering components
   Depending on which hose is being replaced, remove components blocking access. For suction/discharge lines near compressor, remove accessory drive belt cover if necessary. For liquid lines near firewall, remove cowl panels or wiper assembly as needed. Document routing and support bracket locations with photos.
   Torque spec

   Cover Screws12 Nm (9 lb-ft)
3. 3

   Disconnect AC line fittings at compressor
   Using appropriate flare nut wrench, carefully loosen the AC line fitting at the compressor connection. Support the compressor-side fitting with a backup wrench to prevent twisting. Once loosened, remove the fitting completely and immediately cap both openings to prevent contamination and moisture entry.
   ⚠Use two wrenches - one to hold the compressor port and one to turn the fitting. Twisting the compressor port can damage internal components.
4. 4

   Disconnect AC line at condenser or evaporator
   Locate the opposite end of the hose assembly at the condenser (front of vehicle) or evaporator (firewall). Use flare nut wrench to loosen the fitting while supporting the component-side connection. Remove the fitting and cap both openings. Note any mounting brackets or clips securing the line.
5. 5

   Remove hose mounting brackets
   Remove all bolts securing the AC hose assembly to mounting brackets along its routing path. Common locations include engine block brackets, frame rail clips, and firewall supports. Keep all hardware organized for reinstallation.
   ℹ️Take photos of hose routing and support locations before removal for accurate reinstallation.
   Torque spec

   Mounting Bracket Bolts28 Nm (21 lb-ft)
6. 6

   Remove old AC hose assembly
   Carefully extract the AC hose assembly from the engine bay, noting its routing path through various mounting points and around other components. Check for any additional clips or ties securing the hose. Inspect the old hose for signs of failure (kinks, abrasion, oil residue) to identify root cause.
7. 7

   Inspect connections and add PAG oil
   Inspect compressor, condenser, and evaporator ports for damage or debris. Clean with lint-free cloth if needed. Add specified amount of fresh PAG 46 oil to new hose assembly (typically 1-2 oz distributed between connections). Install new O-rings on both ends of the new hose, lubricating with small amount of PAG oil.
   ⚠Only use PAG oil specified for R-1234yf systems. Never use PAG oil from R-134a systems as it may contain incompatible additives.
8. 8

   Route new AC hose assembly
   Route the new AC hose assembly through the engine bay following the exact path of the original hose. Ensure the hose does not contact sharp edges, moving components, or hot surfaces. Position all mounting brackets and support clips along the route.
9. 9

   Connect hose to compressor
   Thread the AC line fitting onto the compressor port by hand until finger-tight. Verify O-ring is properly seated and not pinched. Using torque wrench and flare nut wrench, tighten to specification while holding compressor port with backup wrench.
   ⚠Do not over-tighten AC fittings. Excessive torque can damage flare seats and cause leaks.
   Torque spec

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

    Connect hose to condenser or evaporator
    Thread the opposite end fitting onto the condenser or evaporator port by hand until finger-tight. Verify proper O-ring seating. Torque to specification using torque wrench while supporting the component-side fitting.
    Torque spec

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

    Secure mounting brackets
    Install and torque all mounting bracket bolts that secure the AC hose assembly along its routing path. Ensure hose is properly positioned in all support clips and not under tension or twisted. Verify adequate clearance from all moving and hot components.
    Torque spec

    Mounting Bracket Bolts28 Nm (21 lb-ft)
12. 12

    Vacuum and leak test system
    Connect AC service machine to system. Pull vacuum to at least 29 inches Hg for minimum 30 minutes. Monitor for vacuum decay - system should hold vacuum indicating no leaks. If vacuum holds, proceed to recharge. If vacuum drops, locate and repair leak before charging.
    ⚠Adequate vacuum time is critical to remove all moisture from the system. Moisture can cause compressor failure and reduce cooling performance.
13. 13

    Recharge AC system
    Using AC service machine, recharge system with R-1234yf refrigerant to factory specification (refer to underhood label for exact capacity, typically 1.43-1.65 lbs for 3.5L EcoBoost). Add refrigerant slowly through low-side port. Do not overcharge system.

Reassembly

1. Reinstall any removed air intake ducting, cowl panels, or wiper assemblies
2. Install engine cover by aligning clips and pressing firmly until seated
3. Reinstall accessory drive belt cover if removed
4. Reconnect negative battery cable and tighten securely

Verification

• Start engine and turn AC to maximum cooling with fan on high
• Verify compressor engages and AC clutch cycles properly
• Check center vent temperature - should reach 38-42°F within 5 minutes at idle
• Visually inspect all new connections for signs of refrigerant oil leakage
• Use electronic leak detector or UV light to verify no leaks at fittings
• Verify AC hose assembly has no contact with moving components or excessive vibration
• Monitor AC performance over several days to confirm proper operation

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