This procedure covers the removal and replacement of the high-side AC hose on a 2015-2020 Ford F-150 with the 3.5L EcoBoost V6 engine, including evacuation and recharge of the AC system.

Warnings

Tools required

Parts

• AC high-side hose assembly × 1 — Use OEM specification
• AC line O-rings × 4 — Use OEM specification
• R-134a refrigerant × 1 — Approximately 1.87 lbs total system capacity
• PAG 46 compressor oil × 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 terminal and wait 2 minutes
4. Gather all tools and replacement parts before beginning
5. Verify AC recovery machine is properly calibrated and oil bottle is filled

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to service ports. Connect to low-side port (larger diameter, located on accumulator) and high-side port (smaller diameter, on discharge line near condenser). Follow recovery machine instructions to fully evacuate refrigerant from system. Record amount recovered for recharge reference. Wait 5 minutes after recovery completes to ensure system is fully depressurized.
2. 2

   Access engine compartment components
   Remove engine cover by pulling upward on front edge to release clips, then lifting off. On RWD models, the high-side hose runs from the compressor (driver side of engine) to the condenser at the front of the vehicle. Identify the hose routing and connection points before removal.
3. 3

   Disconnect high-side hose at condenser
   Locate the high-side hose connection at the condenser (front of vehicle, behind grille). Use appropriate wrench to loosen the fitting. Place drip pan below connection to catch residual oil. Once loose, carefully separate the connection and immediately cap both openings to prevent moisture and debris entry. Inspect and discard old O-rings.
   ⚠Small amount of refrigerant oil will drain from fittings. Keep away from painted surfaces and electrical components.
4. 4

   Disconnect high-side hose at compressor
   Trace the high-side hose back to the AC compressor mounted on the driver side of the engine. The discharge fitting is the upper connection on the compressor. Use appropriate wrench to loosen the fitting at the compressor. Separate the connection and cap both the hose and compressor port immediately. Note the routing of the hose through any clips or brackets.
5. 5

   Remove hose mounting brackets
   Release the high-side hose from any mounting clips or brackets along its routing path. Typically there are 2-3 clips securing the hose to the frame rail and engine structure. Gently work the hose free from these mounting points, taking note of exact positions for reinstallation.
6. 6

   Remove old high-side hose
   Carefully maneuver the old hose out of the engine compartment, being careful not to damage surrounding components. Inspect the old hose for signs of failure (cracks, kinks, oil residue, damaged fittings) to identify root cause of failure. Compare new hose to old hose to verify correct replacement part.
7. 7

   Prepare new hose and fittings
   Remove caps from new hose. Install new O-rings on both ends of the new hose - there are typically 2 O-rings per connection point (4 total). Lightly coat each new O-ring with fresh PAG 46 oil. Add approximately 1-2 ounces of PAG oil into the new hose to replace oil lost during service. Do not over-oil as this can damage the AC system.
   ℹ️Use only PAG 46 oil specified for R-134a systems. Do not use PAG oil from opened containers more than 1 year old as it absorbs moisture.
8. 8

   Install new hose
   Route the new high-side hose through the engine compartment following the same path as the original. Ensure hose does not contact hot engine components, sharp edges, or moving parts. Position hose ends at both the compressor and condenser connection points. Verify hose length allows connections without tension or kinking.
9. 9

   Connect hose at compressor
   Remove cap from compressor discharge port. Inspect port threads and sealing surface for damage. Hand-thread the new hose fitting onto the compressor discharge port until fully seated. Use torque wrench to tighten to specification. Ensure fitting is properly aligned and not cross-threaded.
   Torque spec

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

    Connect hose at condenser
    Remove cap from condenser connection point. Hand-thread the new hose fitting onto the condenser until fully seated. Use torque wrench to tighten to specification. Double-check alignment to prevent leaks.
    Torque spec

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

    Secure hose routing
    Install the hose into all mounting clips and brackets noted during removal. Ensure hose follows original routing path and maintains proper clearance from engine components, belts, and exhaust. Verify hose cannot contact moving parts or hot surfaces during engine operation.
12. 12

    Evacuate AC system
    Connect vacuum pump to AC service ports using manifold gauge set. Evacuate system to at least 29 inches of mercury (98 kPa vacuum). Maintain vacuum for minimum 30 minutes. Monitor for vacuum loss - if vacuum drops more than 2 inches in 30 minutes, there is a leak that must be repaired before proceeding. After successful vacuum hold test, close valves and disconnect vacuum pump.
    ⚠Inadequate evacuation will leave moisture in system which can freeze at expansion valve and damage compressor. Always evacuate for full 30 minutes minimum.
13. 13

    Recharge AC system
    Using AC recharge equipment, add refrigerant to system. Total system capacity is approximately 1.87 lbs (30 oz) of R-134a. Charge to the amount recovered in Step 1, or to factory specification if significantly different. Monitor system pressures during charging. Low side should be 25-45 PSI and high side 200-250 PSI with engine at idle and AC on max cool (ambient temperature dependent).
14. 14

    Leak test system
    With system charged, use electronic leak detector to check both new connections at the compressor and condenser. Also check service port caps and any disturbed connections. Spray soapy water on fittings and watch for bubbles. Start engine and run AC on max cool for 5 minutes, then recheck all connections for leaks.

Reassembly

1. Reinstall engine cover by aligning rear tabs first, then pressing down firmly on front clips until seated
2. Reconnect negative battery terminal and tighten securely
3. Clear any AC-related diagnostic codes using scan tool if equipped

Verification

• Start engine and turn AC to maximum cool with blower on high
• Verify cold air from vents within 2-3 minutes of operation
• Check that compressor clutch engages and cycles normally
• Monitor AC system pressures: low side should be 25-45 PSI, high side 200-250 PSI at idle (varies with ambient temperature)
• Verify no unusual noises from compressor or hissing sounds indicating leaks
• Inspect all connection points for signs of refrigerant oil leakage after 24 hours of operation
• Confirm vent temperature is 35-45°F colder than ambient temperature

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