AC Hose - High Side

This procedure covers the removal and replacement of the high-side AC hose on a 2017 Maserati Levante with 3.0L V6 Twin Turbo engine, including refrigerant recovery, hose replacement, and system recharge.

Warnings

Tools required

Parts

• AC high-side hose assembly × 1 — Use OEM specification
• AC line O-rings (various sizes) × 1 — Use OEM specification
• R-134a refrigerant × 1 — Per system capacity specification
• PAG oil (compatible with system) × 1 — Use OEM specification
• UV dye (if not pre-installed) × 1 — Use OEM specification

Preparation

1. Verify AC system complaint and document current operation before beginning work
2. Ensure vehicle is parked on level surface in well-ventilated area
3. Allow engine and AC system to cool completely (minimum 2 hours)
4. Disconnect negative battery terminal and wait 10 minutes for system capacitor discharge
5. Remove engine cover by pulling upward on four retention points
6. Document refrigerant amount recovered for proper recharge quantity

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to service ports (low side on accumulator, high side near condenser). Follow machine instructions to fully recover all refrigerant from system. Record the amount recovered. Allow system to stabilize at 0 PSI for at least 5 minutes to verify no residual pressure remains.
2. 2

   Access high-side hose at compressor
   The high-side hose connects to the compressor on the passenger side of the engine bay. Remove any plastic covers or shields blocking access to the compressor area. On the Levante, you may need to remove the forward undershield for better access to lower connections.
   Torque spec

   Cover Screws11 Nm (8 lb-ft)
3. 3

   Disconnect high-side hose at compressor
   Using a line wrench to prevent rounding, carefully loosen the high-side hose fitting at the compressor discharge port. Once loose, unthread by hand and remove the hose. Immediately cap both the compressor port and hose end to prevent contamination. Remove and discard the O-rings from the fitting.
   ⚠If any refrigerant escapes during disconnection, STOP immediately. System was not fully recovered and could cause injury.
4. 4

   Trace and disconnect condenser connection
   Follow the high-side hose from the compressor toward the condenser at the front of the vehicle. The hose typically routes along the passenger side frame rail. Locate the connection point at the condenser (usually near the top). Use a line wrench to disconnect the fitting at the condenser. Cap both openings immediately and remove O-rings.
5. 5

   Remove hose from vehicle
   The high-side hose is secured with clips and brackets along its routing path. Working from compressor to condenser, release all mounting clips and brackets. Note the exact routing and clip positions for reinstallation. Carefully extract the hose from the engine bay, avoiding contact with sharp edges or hot components.
6. 6

   Inspect system components
   With hose removed, inspect both the compressor discharge port and condenser inlet for debris, metal particles, or oil residue. Clean ports with lint-free cloth if needed. Check compressor clutch for free rotation and bearing noise. Inspect condenser for external damage or leaks. Any contamination indicates possible compressor failure requiring additional service.
   ⚠Metal particles or black residue indicate compressor failure. System must be flushed and compressor replaced before installing new hose.
7. 7

   Prepare new high-side hose
   Remove caps from new hose immediately before installation. Install new O-rings on both hose fittings (supplied with hose or purchased separately). Lightly coat O-rings with fresh PAG oil compatible with the system (typically PAG 46 for Levante). Add approximately 10-15ml of PAG oil into the hose itself to replace oil lost with old hose.
8. 8

   Route and position new hose
   Route the new high-side hose along the same path as the original, ensuring it follows factory routing exactly. Position hose so fittings align with compressor and condenser ports without tension or kinking. Secure hose with original clips and brackets, but do not fully tighten mounting hardware yet.
9. 9

   Connect hose at compressor
   Remove cap from compressor discharge port. Thread the high-side hose fitting onto compressor by hand, ensuring O-ring seats properly and threads engage smoothly. Once hand-tight, use torque wrench and line wrench to tighten to specification. Do not overtighten as this can damage O-rings and cause leaks.
   Torque spec

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

    Connect hose at condenser
    Remove cap from condenser inlet port. Thread the high-side hose fitting onto condenser by hand, verifying smooth thread engagement and proper O-ring seating. Torque to specification using torque wrench and line wrench to prevent fitting damage.
    Torque spec

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

    Secure hose routing and hardware
    With both connections torqued, verify hose routing has no kinks, sharp bends, or contact with moving parts or hot surfaces. Tighten all mounting clips and bracket hardware to secure the hose in proper position. Ensure minimum 1 inch clearance from exhaust manifolds and turbochargers.
    Torque spec

    Mounting Bracket Bolts26 Nm (19 lb-ft)
12. 12

    Evacuate AC system
    Connect vacuum pump to AC service ports. Evacuate system to full vacuum (29.9 inches Hg or -101 kPa) and maintain for minimum 45 minutes. Close valves and observe vacuum for 10 minutes. Vacuum should hold steady, indicating no leaks. If vacuum drops more than 1 inch Hg, locate and repair leak before proceeding.
    ℹ️Proper evacuation is critical to remove all moisture from the system. Moisture causes corrosion and compressor damage.
13. 13

    Recharge AC system
    With system under vacuum, connect refrigerant supply (use recorded recovery amount or factory specification, typically 650-750 grams for Levante). Charge system through low-side port only, with engine running and AC on maximum cold. Monitor pressure and temperature. Add UV dye if not already present in system. Final pressures should be approximately 30-45 PSI low side and 200-250 PSI high side at idle with ambient temperature around 75°F.

Reassembly

1. Reinstall any shields or covers removed for access, torquing fasteners to specification
2. Reinstall engine cover by aligning and pressing down on retention points until clicks are heard
3. Reconnect negative battery terminal and verify no warning lights appear
4. Clear any AC-related fault codes from vehicle computer using scan tool

Verification

• Start engine and set AC to maximum cold with high blower speed
• Verify compressor clutch engages and remains engaged consistently
• Check vent temperature reaches 38-42°F within 5 minutes of operation
• Inspect all AC line connections for oil seepage or frost indicating leaks
• Use leak detector around all connections, especially new high-side hose fittings
• Monitor system pressures: low side should be 30-45 PSI, high side 200-250 PSI at idle with 75°F ambient
• Verify no unusual noises from compressor or abnormal cycling
• Test drive vehicle and confirm AC operates properly under all conditions

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