This procedure covers the removal and replacement of the AC hose assembly on a 2015-2020 Ford F-150 with 3.5L EcoBoost engine, including refrigerant recovery, hose replacement, and system recharge.

Warnings

Tools required

Parts

• AC hose assembly (specific to routing needed) × 1 — Use OEM Ford specification for correct routing
• AC line O-rings × 4 — Use OEM specification
• R-134a refrigerant × 1 — Approximately 1.75 lbs
• PAG 46 compressor oil × 1 — Use OEM Ford specification
• UV leak detection dye (optional) × 1 — Use with R-134a

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure engine is completely cool to the touch
3. Disconnect negative battery terminal and wait 2 minutes for airbag system discharge
4. Verify you have the correct replacement AC hose assembly for your specific routing (suction, discharge, or liquid line)
5. Identify which AC hose requires replacement (most common: suction line between evaporator and compressor, or discharge line from compressor to condenser)

Procedure

1. 1

   Recover refrigerant from AC system
   Connect AC recovery machine to both high and low side service ports. Follow machine instructions to completely recover all refrigerant from the system. Document the amount of refrigerant and oil recovered. This is a legal requirement and ensures proper recharge quantities. The system should pull into vacuum indicating complete recovery.
   ⚠️Only certified technicians with EPA 609 certification should perform refrigerant recovery. Improper recovery can result in refrigerant release and legal penalties.
2. 2

   Access the damaged AC hose
   For suction line: Remove the engine cover by lifting at the rear tabs. For discharge line: May require removal of radiator sight shield or partial grille removal. For liquid line to evaporator: Access from underneath vehicle, may require partial splash shield removal. Identify all mounting clips and brackets securing the hose assembly.
   ℹ️Take photos of hose routing and clip locations before removal to ensure correct reinstallation.
3. 3

   Remove hose mounting hardware
   Disconnect any electrical connectors for AC pressure sensors if attached to the hose being replaced. Remove mounting bolts or clips securing the AC hose to the engine block, frame, or body. Common locations include brackets near the compressor, along the firewall, and near the condenser. Keep track of all hardware for reinstallation.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
4. 4

   Disconnect AC hose at compressor end
   Using appropriate wrench size, loosen the AC line fitting at the compressor. For the 3.5L EcoBoost, the compressor is located on the front driver side of the engine. Use a backup wrench on the compressor port to prevent turning the compressor fitting. Once loose, remove the fitting completely and immediately cap both the hose end and compressor port to prevent moisture entry. Remove and discard old O-rings.
   ⚠Verify refrigerant has been fully recovered before loosening fittings. Any residual pressure indicates incomplete recovery.
   Torque spec

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

   Disconnect AC hose at opposite end
   Disconnect the other end of the hose assembly. For suction line: at the evaporator connection through the firewall. For discharge line: at the condenser inlet. For liquid line: at the evaporator outlet or orifice tube location. Use backup wrench to prevent component damage. Cap all openings immediately. Remove and discard old O-rings from both ends.
   ⚠Do not allow dirt, debris, or moisture to enter any AC system components. Even small contamination can cause system failure.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
6. 6

   Remove old AC hose assembly
   Carefully maneuver the old hose assembly out of the engine bay, noting its routing path. The hose must follow the same path to avoid contact with hot exhaust components or moving parts. Remove any remaining clips or ties securing the hose. Inspect the routing area for any sharp edges or damage that may have caused the original hose failure.
   ℹ️If the hose failed due to abrasion or contact damage, identify and correct the root cause before installing the new hose.
7. 7

   Prepare new AC hose assembly
   Unpack the new AC hose assembly and verify it matches the old hose configuration. Install new O-rings on both ends of the new hose. Lightly coat the new O-rings with PAG 46 compressor oil to aid installation and prevent damage. Add the appropriate amount of fresh PAG oil to the system based on manufacturer specifications (typically 1-2 oz if replacing a hose). Do not remove protective caps from hose ends until immediately before installation.
   ⚠Use only the correct PAG oil viscosity (PAG 46) for the Ford 3.5L EcoBoost AC system. Wrong oil type can damage the compressor.
8. 8

   Route new AC hose assembly
   Following the exact path of the original hose, route the new hose assembly through the engine bay. Ensure the hose does not contact exhaust manifolds, sharp edges, or moving components like the accessory belt. The hose should have adequate clearance and follow factory routing clips. Install any intermediate mounting brackets or clips loosely at this stage.
   ⚠Improper routing can cause premature hose failure from heat or abrasion. Verify at least 1 inch clearance from exhaust components.
9. 9

   Connect hose at first fitting location
   Remove the cap from one end of the new hose and the corresponding component port. Verify the O-ring is properly seated in the hose fitting groove. Thread the fitting by hand first to ensure proper alignment and prevent cross-threading. Once hand-tight, use a torque wrench to tighten to specification while using a backup wrench on the component port.
   ⚠Cross-threading AC fittings will damage expensive components. Always start threads by hand and verify smooth rotation.
   Torque spec

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

    Connect hose at second fitting location
    Remove the cap from the other end of the hose and component port. Check O-ring position, then hand-thread the fitting. Torque to specification using backup wrench. Verify both connections are secure and O-rings have not been pinched or displaced during installation.
    Torque spec

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

    Secure hose mounting hardware
    Install and torque all mounting bolts securing the hose assembly to brackets, engine block, or body. Ensure all factory clips and ties are reinstalled to prevent hose movement. Reconnect any AC pressure sensor electrical connectors. Verify the hose has no kinks and maintains proper clearance from all moving and hot components.
    Torque spec

    Mounting Bolts31 Nm (23 lb-ft)
12. 12

    Evacuate AC system
    Connect the AC evacuation equipment to both service ports. Pull a vacuum on the system for a minimum of 30 minutes (45 minutes recommended for best moisture removal). The system should reach and hold at least 29 inches of mercury vacuum. After evacuation, close valves and monitor for 10 minutes - vacuum should not rise more than 2 inches, indicating no leaks.
    ⚠Inadequate evacuation leaves moisture in the system which will freeze at the expansion device and damage the compressor. Do not rush this step.
13. 13

    Recharge AC system
    Using the refrigerant machine or manifold gauges, recharge the system with the documented amount of R-134a recovered earlier (typically 1.65-1.85 lbs for 3.5L EcoBoost F-150). Add UV dye if desired for future leak detection. Monitor pressures during charging. Do not overcharge the system. Final pressures should be approximately 30-40 PSI low side and 200-250 PSI high side at idle with AC on and 75°F ambient temperature.
    ⚠Overcharging can cause compressor damage and poor cooling performance. Use exact recovered amount or manufacturer specifications.
14. 14

    Leak test and verify operation
    With the system charged, start the engine and activate the AC system at maximum cold setting. Using a leak detector or soap solution, check all disturbed fittings for leaks. Monitor system pressures for proper operation. Verify clutch engagement, no unusual noises from compressor, and cold air output from vents. Check that pressures stabilize within normal ranges.
    ℹ️Small leaks may not be immediately apparent. A pressure drop over 24 hours indicates a leak that must be corrected.

Reassembly

1. Reinstall any removed splash shields, grille components, or engine covers
2. Reconnect the negative battery terminal
3. Clear any diagnostic trouble codes related to AC system if present
4. Verify all tools and caps have been removed from the engine bay

Verification

• Start engine and run AC on maximum cold for 10 minutes, verify center vent temperature is 38-45°F
• Check that compressor cycles appropriately and no unusual noises are present
• Verify low side pressure is 30-40 PSI and high side is 200-250 PSI at idle with 75°F ambient temperature
• Inspect all hose connections for signs of oil weeping or refrigerant leaks
• Confirm hose routing has proper clearance from exhaust and moving components
• Test drive vehicle and verify AC cooling performance under load
• If UV dye was added, use UV light to inspect for any fluorescent traces indicating leaks

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