AC Orifice Tube

This procedure replaces the AC orifice tube, a flow-metering device located in the liquid line between the condenser and evaporator that filters refrigerant and controls flow rate.

Warnings

Tools required

Parts

• AC orifice tube × 1 — Use OEM specification
• AC line O-rings × 4 — Use OEM specification
• R-134a refrigerant × 1 — Verify spec on underhood label
• PAG 46 compressor oil × 1 — Use OEM specification

Preparation

1. Verify AC system refrigerant type using refrigerant identifier (should be R-134a for this model year range)
2. Park vehicle on level surface and apply parking brake
3. Allow engine and AC system to cool completely (minimum 2 hours)
4. Gather replacement orifice tube, O-rings, and required quantity of PAG oil
5. Connect AC recovery machine and verify it is certified and functioning properly

Procedure

1. 1

   Recover refrigerant from system
   Connect AC recovery machine to service ports. Follow machine instructions to completely recover all refrigerant from the system. Record the amount recovered to determine proper recharge quantity. Allow recovery machine to run until vacuum holds steady, indicating complete recovery.
2. 2

   Locate orifice tube assembly
   Open hood and locate the liquid line connection at the evaporator inlet on the passenger side firewall. The orifice tube is inside the liquid line fitting entering the evaporator. On 2016-2024 Tucson models, this is typically a horizontal line with a slight bulge or dimple indicating the orifice tube location inside.
3. 3

   Disconnect liquid line at evaporator inlet
   Using appropriate flare nut wrench or AC line disconnect tool, carefully disconnect the liquid line fitting at the evaporator inlet where the orifice tube is located. Be prepared for residual oil to drain. Immediately cap or plug both the line and evaporator opening to prevent moisture and debris entry. Remove and discard old O-rings from the fitting.
4. 4

   Extract old orifice tube
   Using the orifice tube removal tool, carefully extract the old orifice tube from inside the liquid line or evaporator inlet (location varies by production date - check both). The tube has a mesh screen on one end and may be stuck due to refrigerant oil residue. Gently twist and pull - do not use excessive force that could break the tube. If broken pieces remain inside, they must be completely removed.
5. 5

   Inspect old orifice tube and system
   Examine the removed orifice tube screen for metal debris, which indicates compressor failure requiring additional repairs. Check for black contamination indicating desiccant breakdown from the receiver-drier. If significant debris is present, the entire system requires flushing and the compressor may need replacement. Clean debris from the line opening with a lint-free cloth.
6. 6

   Install new orifice tube
   Lightly coat the new orifice tube O-rings with clean PAG oil. Ensure the tube is oriented correctly (inlet side typically has longer screen or marking). Insert the new orifice tube into the liquid line or evaporator inlet opening (match original location) by hand, pushing firmly until it seats completely. The tube should sit flush or slightly recessed - verify it cannot be pushed further.
7. 7

   Install new O-rings on line fitting
   Install new O-rings onto the liquid line fitting. Lightly coat O-rings with clean PAG oil - use approximately 2-3 drops per O-ring. Do not use petroleum-based lubricants. Verify O-rings are properly seated in their grooves without twisting or damage.
8. 8

   Reconnect liquid line
   Align and carefully thread the liquid line fitting back onto the evaporator inlet by hand to avoid cross-threading. Once hand-tight, use torque wrench and appropriate socket or wrench to tighten to specification.
   Torque spec

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

   Add replacement PAG oil
   Add fresh PAG 46 oil to replace oil lost during service. If less than 1 oz of oil drained during disassembly, add 1 oz. If 1-2 oz drained, add 2 oz. Add oil through the compressor service port or low-side service port using appropriate oil injector tool.
10. 10

    Evacuate system
    Connect vacuum pump to AC service ports. Evacuate system to full vacuum (minimum 29 inches Hg) and maintain for at least 30-45 minutes. This removes moisture and air. If vacuum does not hold, there is a leak that must be repaired before proceeding.
11. 11

    Recharge AC system
    Using AC recharge machine or manifold gauge set, recharge system with the specified amount of R-134a refrigerant as listed on the underhood specifications label (typically 18-22 oz for this model). Charge through the low-side port with engine running and AC on maximum cold. Monitor pressures to ensure proper fill - low side should be 25-45 psi, high side 200-250 psi at idle with ambient temperature around 75-85°F.
12. 12

    Check for leaks
    With system charged and running, use electronic leak detector or UV dye to inspect all AC line connections, especially the repaired liquid line fitting at the evaporator. Check compressor, condenser, and all service ports. If any leaks are detected, recover refrigerant, repair leak, and repeat evacuation and recharge procedures.

Reassembly

1. Verify all AC line connections are tight and properly torqued
2. Ensure no tools or parts were left in engine compartment
3. Check that all protective caps are removed from service ports

Verification

• Start engine and turn AC to maximum cold with fan on high
• Allow system to run for 5-10 minutes to stabilize
• Verify cold air is blowing from vents (center vent temperature should be 38-45°F with 75-85°F ambient)
• Check that compressor clutch engages and disengages normally
• Monitor system pressures: low side 25-45 psi, high side 200-250 psi at idle (values vary with ambient temperature)
• Verify no abnormal noises from compressor or expansion area
• Confirm no refrigerant smell or visible oil leaks at repaired connections
• Test AC performance during short test drive to ensure consistent cooling

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