AC Hose - Low Side

Replace the low-side AC hose on a 2017 Maserati Levante 3.0L V6 Twin Turbo, including refrigerant recovery, hose removal, installation with new O-rings, and system recharge.

Warnings

Tools required

Parts

• AC low-side hose assembly × 1 — Use OEM specification
• AC line O-ring kit × 1 — Use OEM specification
• PAG 46 compressor oil × 1 — 30-50ml
• R-134a refrigerant × 1 — Approximately 850g total system capacity

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine and AC system to cool completely (minimum 30 minutes)
3. Disconnect negative battery terminal and wait 5 minutes for system discharge
4. Gather all tools, parts, and new O-rings before beginning work
5. Verify AC recovery machine is properly calibrated and has adequate storage capacity

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to both high and low-side service ports. Follow machine manufacturer's instructions to fully recover all refrigerant from the system. Record the amount recovered for recharge reference. Ensure system pressure reads 0 psi before proceeding.
2. 2

   Access low-side AC hose
   Remove the engine cover by pulling upward on the clips. For RWD models, the low-side hose runs from the evaporator (firewall passenger side) to the accumulator/drier near the compressor on the driver side. Remove any plastic covers or heat shields obstructing access to the hose routing using appropriate tools.
   Torque spec

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

   Disconnect evaporator-side fitting
   Locate the low-side hose connection at the evaporator near the firewall. Using the appropriate AC line disconnect tool, carefully separate the spring-lock or threaded fitting. If threaded, use a flare nut wrench to avoid rounding the fitting. Cap the evaporator port immediately to prevent moisture and contamination entry. Remove and discard old O-rings.
4. 4

   Disconnect accumulator/drier-side fitting
   Trace the low-side hose to its connection at the accumulator/drier assembly near the compressor. Disconnect the fitting using the proper line disconnect tool or flare nut wrench. Cap the accumulator port immediately. Remove and discard old O-rings. Inspect both connection points for damage or corrosion.
5. 5

   Remove hose mounting brackets
   The low-side hose is secured to the chassis and engine bay with mounting brackets and clips. Remove all mounting bracket bolts along the hose routing path. Carefully note routing and clip positions for reinstallation. Remove the complete hose assembly from the vehicle.
   Torque spec

   Mounting Bracket Bolts26 Nm (19 lb-ft)
6. 6

   Prepare new AC hose
   Unpack the new low-side AC hose. Install new O-rings on both connection ends, ensuring they are properly seated in their grooves. Lightly coat each O-ring with fresh PAG 46 compressor oil (approximately 5ml per O-ring). Do not use petroleum-based lubricants. Add the manufacturer-specified amount of PAG oil (typically 30-50ml total) into the new hose through one end.
7. 7

   Route and position new hose
   Route the new low-side hose along the exact path of the original, ensuring it does not contact hot engine components, sharp edges, or moving parts. Position all mounting brackets in their original locations. Verify the hose has adequate clearance and no kinks or tight bends that could restrict refrigerant flow.
8. 8

   Connect evaporator-side fitting
   Remove the cap from the evaporator port. Verify the new O-ring is properly positioned and lubricated. Connect the hose to the evaporator fitting, ensuring it fully seats. If threaded, hand-tighten first, then torque to specification using a flare nut wrench. If spring-lock type, push firmly until you hear/feel the lock engage.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
9. 9

   Connect accumulator/drier-side fitting
   Remove the cap from the accumulator port. Verify the new O-ring is properly positioned and lubricated. Connect the hose to the accumulator fitting, ensuring it fully seats. Torque threaded fittings to specification or verify spring-lock engagement. Check both connections for proper seating.
   Torque spec

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

    Secure mounting brackets
    Install and torque all mounting bracket bolts to secure the low-side hose in position. Ensure the hose is properly supported along its entire length and has not shifted from its intended routing. Double-check clearances to all surrounding components.
    Torque spec

    Mounting Bracket Bolts26 Nm (19 lb-ft)
11. 11

    Vacuum test AC system
    Connect the vacuum pump to the AC system service ports. Pull a deep vacuum (minimum 29 inches Hg or 98 kPa) for at least 45 minutes. Close service port valves and monitor vacuum gauge for 30 minutes. If vacuum holds steady, system is leak-free. If vacuum drops, locate and repair leak before proceeding.
12. 12

    Recharge AC system
    Using the AC recharge machine, charge the system with the correct amount of R-134a refrigerant (refer to underhood label, typically 850g ±50g for this model). Add UV dye if desired for future leak detection. Follow machine instructions for proper charging procedure. Verify both high and low-side pressures are within specification.
13. 13

    Reinstall covers and reconnect battery
    Reinstall any heat shields, plastic covers, and the engine cover that were removed. Torque cover screws to specification. Reconnect the negative battery terminal. Clear any diagnostic trouble codes that may have been stored due to battery disconnect.
    Torque spec

    Cover Screws11 Nm (8 lb-ft)

Reassembly

1. Ensure all AC line fittings are torqued to specification with new O-rings installed
2. Verify hose routing matches original path with proper clearances
3. Confirm all mounting brackets are secured and hose is properly supported
4. Double-check that no tools or parts were left in the engine bay

Verification

• Start engine and set AC to maximum cold with fan on high speed
• Allow system to run for 10 minutes and verify cold air output (vent temperature should be 40-50°F / 4-10°C)
• Check both AC line connections for refrigerant leaks using electronic leak detector or soap solution
• Verify compressor cycles normally and system pressures are within specification (low side: 25-40 psi, high side: 200-300 psi at idle, ambient 75°F)
• Inspect UV dye with black light if installed, looking for any signs of leakage
• Listen for any unusual noises from compressor or hissing sounds indicating leaks
• Verify no warning lights or AC-related fault codes are present in vehicle diagnostics

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