AC Orifice Tube

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

Warnings

Tools required

Parts

• AC orifice tube × 1 — Use OEM specification
• AC line O-rings × 4 — Use OEM specification
• PAG oil (ND-11 or equivalent) × 1 — Use OEM specification

Fluids

• R-1234yf refrigerant

Preparation

1. Ensure engine is cool to the touch (wait minimum 30 minutes after operation)
2. Park vehicle on level surface and engage parking brake
3. Verify you have proper EPA 609 certification to handle R-1234yf refrigerant
4. Connect AC recovery machine and completely evacuate refrigerant from system following equipment manufacturer procedures
5. Record refrigerant amount recovered for proper recharge quantity
6. Disconnect negative battery terminal and wait 3 minutes for airbag system discharge
7. Remove engine cover by pulling upward on four retaining clips

Procedure

1. 1

   Locate the orifice tube
   The orifice tube is located in the liquid line between the condenser and evaporator, accessed from the engine bay on the passenger side near the firewall. Identify the liquid line (smaller diameter line) coming from the condenser. The orifice tube is typically housed at a connection point with a slightly larger diameter section.
2. 2

   Remove liquid line connection at orifice tube location
   Using a flare nut wrench to prevent rounding, loosen and remove the liquid line fitting at the orifice tube housing. The fitting connects on both sides of the orifice tube chamber. Remove both connection fittings. Immediately cap open lines with clean plugs to prevent moisture and debris contamination. Inspect and discard old O-rings.
3. 3

   Extract the orifice tube
   Insert the orifice tube removal tool into the line opening. The tool should engage the tabs or body of the orifice tube. Twist gently while pulling outward to extract the tube. If tube is stuck due to debris or corrosion, spray a small amount of AC flush around the edges and retry. Do not use excessive force as this may push debris further into system or break the tube.
4. 4

   Inspect removed orifice tube
   Carefully examine the removed orifice tube and screen for metal shavings, black debris, or excessive contamination. Small amounts of dark oil residue are normal. Metal particles indicate compressor failure and require complete system flush and compressor replacement. If contamination is severe, stop procedure and assess full system condition before continuing.
5. 5

   Clean orifice tube cavity
   Using clean shop towels and approved AC system flush solvent, thoroughly clean the cavity where orifice tube sits. Ensure no debris, old O-ring material, or contaminants remain. Flush small amounts of solvent through and collect in towels. Allow cavity to air dry completely before installation.
6. 6

   Prepare new orifice tube
   Remove new orifice tube from packaging. Verify the correct part number and that the flow direction arrow (if present) matches orientation of old tube. Lightly coat the new tube body with fresh PAG oil (ND-11 specification) to ease installation and ensure proper lubrication. Do not use excessive oil.
7. 7

   Install new orifice tube
   Carefully insert the new orifice tube into the line cavity, ensuring correct orientation with flow arrow pointing toward evaporator (passenger compartment direction). Push firmly until tube seats completely against internal stop. The tube should sit flush or slightly recessed. Verify tube is fully seated and cannot be pulled out easily by hand.
8. 8

   Install new O-rings on line fittings
   Place new O-rings in the grooves on both liquid line fittings. Coat O-rings lightly with fresh PAG oil. Inspect O-ring grooves on line and housing for damage or debris and clean if needed. Ensure O-rings are properly seated in grooves and not twisted or pinched.
9. 9

   Reconnect liquid line fittings
   Thread liquid line fittings by hand onto the orifice tube housing connections. Ensure fittings thread smoothly without resistance. Once hand-tight, use flare nut wrench and torque wrench to tighten to specification. Apply torque evenly and smoothly.
   Torque spec

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

    Add replacement PAG oil to system
    Add PAG oil to compensate for oil lost during recovery and trapped in old orifice tube. Add 20-30ml of ND-11 specification PAG oil through service port or compressor depending on amount recovered and manufacturer guidelines. If significant oil was drained during recovery, adjust quantity accordingly.
11. 11

    Vacuum and leak test system
    Connect vacuum pump to AC service ports. Pull vacuum to minimum 500 microns for at least 30 minutes. System should hold vacuum without rising more than 100 microns over 10 minute observation period. If vacuum rises significantly, locate and repair leak before proceeding. A proper vacuum removes all moisture from system.
12. 12

    Recharge AC system
    Using AC recovery/recharge machine and electronic scale, recharge system with exact amount of R-1234yf refrigerant recorded during recovery (typically 400-500g total system capacity for this model). Follow machine instructions for proper liquid or vapor charging method. Do not overcharge system.
13. 13

    Reinstall engine cover and battery
    Reinstall engine cover by aligning four clips and pressing down firmly until all clips engage. Reconnect negative battery terminal. Clear any DTCs that may have set during battery disconnect using OBD-II scanner if needed.

Reassembly

1. Ensure all AC line fittings are torqued to specification and properly seated
2. Verify no tools or parts are left in engine bay
3. Confirm engine cover is securely clipped in place
4. Double-check that proper refrigerant quantity was charged into system

Verification

• Start engine and turn AC to maximum cold setting with fan on high
• Allow system to run for 5 minutes and verify compressor engages and cycles normally
• Check that center dash vents blow cold air (should be 40-50°F at vent with 80°F ambient)
• Using manifold gauges, verify system pressures are within specification (typically 25-35 psi low side, 180-250 psi high side at idle with 80°F ambient)
• Inspect all AC line connections for oil seepage or refrigerant leaks using electronic leak detector
• Check that AC system maintains cold temperature during 10 minute test drive
• Listen for abnormal noises from compressor or expansion areas indicating restriction or debris

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