AC Orifice Tube

Replace the AC orifice tube in the air conditioning system to restore proper refrigerant flow and system performance.

Warnings

Tools required

Parts

• AC orifice tube × 1 — Use OEM specification
• AC line O-rings × 1 — Use OEM specification
• PAG oil for electric vehicle compressor × 1 — R-1234yf compatible
• R-1234yf refrigerant × 1 — As required by system capacity

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect the 12-volt auxiliary battery negative terminal and wait 2 minutes
3. Open the Rivian service mode through the vehicle interface to disable high voltage system (consult service manual for exact procedure)
4. Verify high voltage system is isolated using appropriate lockout/tagout procedures
5. Connect AC recovery machine and verify it is approved for R-1234yf refrigerant
6. Record the amount of refrigerant recovered for recharge reference
7. Allow system to stabilize at ambient temperature for accurate pressure readings

Procedure

1. 1

   Recover AC refrigerant
   Connect the AC recovery machine to the high and low side service ports. Follow the machine manufacturer's instructions to completely recover all R-1234yf refrigerant from the system. Record the amount recovered, as this will guide the recharge amount. Wait until the machine indicates recovery is complete and the system has reached zero pressure.
2. 2

   Access the orifice tube location
   On the Rivian EDV 500, locate the liquid line between the condenser and evaporator. The orifice tube is typically installed in the inlet line at the evaporator or within a specialized fitting in the liquid line near the firewall. Remove any protective covers or panels necessary to access this connection point. Clean the area thoroughly to prevent contamination.
3. 3

   Disconnect the liquid line
   Using the appropriate line disconnect tool, separate the liquid line at the connection point where the orifice tube is located. On Rivian systems, this is typically a spring-lock or quick-disconnect fitting. Apply gentle pressure with the disconnect tool while pulling the line apart. Have lint-free towels ready to catch any residual refrigerant oil.
4. 4

   Remove the old orifice tube
   Using the orifice tube removal tool, carefully extract the old orifice tube from its housing. Insert the removal tool into the line, engage the tabs or edges of the orifice tube, and pull straight out. If the tube is stuck due to debris or corrosion, work it gently back and forth while pulling. Inspect the removed tube for debris or metal particles which indicate compressor damage.
5. 5

   Inspect and clean the line
   Examine the interior of both line connections for debris, metal particles, or contamination. If metal particles are present, the system requires flushing and the compressor may need replacement. Clean the connection surfaces with lint-free towels. Ensure no foreign material remains in the line that could contaminate the new orifice tube.
6. 6

   Install new O-rings
   Remove the old O-rings from both sides of the connection. Inspect the O-ring sealing surfaces for damage or scoring. Lubricate new O-rings with clean PAG oil compatible with R-1234yf systems and electric vehicle compressors. Install the new O-rings in their grooves, ensuring they are seated properly without twists or damage.
7. 7

   Install the new orifice tube
   Lubricate the new orifice tube O-rings with clean PAG oil. Note the directional arrow on the orifice tube body - it must point in the direction of refrigerant flow toward the evaporator. Insert the orifice tube straight into the line until it seats completely. The tube should be fully inserted with the tabs properly positioned to prevent it from backing out.
8. 8

   Reconnect the liquid line
   Align the liquid line connections and push together firmly until you hear or feel the locking mechanism engage. Pull on both sides of the connection to verify it is fully locked. The connection should not separate under moderate pulling force. Verify the O-rings did not roll or pinch during connection.
9. 9

   Add replacement PAG oil
   Add the appropriate amount of PAG oil to compensate for oil lost during the procedure. For orifice tube replacement, typically 1-2 ounces is sufficient unless significant oil was lost. Use only PAG oil specified for electric vehicle AC compressors and R-1234yf systems. Add through the low side service port or compressor fill port as applicable.
10. 10

    Evacuate the system
    Connect the vacuum pump to the AC service ports through the manifold gauge set. Evacuate the system to at least 29 inches of mercury vacuum. Maintain this vacuum for a minimum of 45 minutes for the Rivian EDV 500 system. After evacuation, close the valves and monitor for 10 minutes - vacuum should hold steady indicating no leaks.
11. 11

    Recharge the AC system
    Using the AC recharge machine, add R-1234yf refrigerant to the system. Charge with the amount recovered (if clean) or according to Rivian specifications (typically displayed on the underhood label). Charge through the low side port with the system in service mode. Monitor pressures and ensure refrigerant is entering the system properly.
12. 12

    Reconnect electrical systems
    Exit service mode on the Rivian vehicle interface. Reconnect the 12-volt auxiliary battery negative terminal. Wait for the vehicle systems to initialize fully. Verify no warning lights are illuminated on the instrument cluster related to the AC or high voltage systems.

Reassembly

1. Reinstall any protective covers or panels removed during access
2. Verify all AC line connections are secure and properly locked
3. Check that no tools or materials were left in the engine compartment
4. Ensure high voltage system lockout devices are removed if used

Verification

• Start the vehicle and enable the AC system at maximum cooling
• Verify compressor engages and system operates smoothly without unusual noises
• Check that both high and low side pressures are within specification using manifold gauges (typically 35-55 PSI low side, 180-250 PSI high side at 75°F ambient)
• Confirm cold air output at dashboard vents reaches appropriate temperature (typically 38-45°F)
• Inspect all connection points for signs of refrigerant leakage using electronic leak detector or UV dye
• Use scan tool to verify no AC-related fault codes are present
• Test system operation through multiple modes (vent positions, temperature settings) to ensure proper function
• Allow system to run for 10-15 minutes and recheck pressures for stability

More procedures for this vehicle