AC Hose - High Side

Replace the high-side AC hose on a 2023 Chevrolet Bolt EUV, including refrigerant recovery, hose removal, installation with new O-rings, and system recharge.

Warnings

Tools required

Parts

• AC high-side hose assembly × 1 — Use OEM specification
• AC line O-rings × 4 — Use OEM specification
• PAG oil (appropriate viscosity for system) × 1 — Use OEM specification

Fluids

• R-1234yf refrigerant

Preparation

1. Verify the AC refrigerant type (R-1234yf) from the underhood label
2. Park vehicle on level surface and engage parking brake
3. Turn off vehicle completely and remove key fob from vehicle interior
4. Allow AC system to equalize pressure for at least 10 minutes
5. Gather EPA-certified AC recovery equipment and ensure proper operation
6. Locate high-side AC hose routing from condenser to compressor

Procedure

1. 1

   Recover refrigerant from AC system
   Connect AC recovery machine to both high and low-side service ports. Follow recovery machine instructions to completely evacuate all refrigerant from the system. Record the amount of refrigerant recovered for recharge reference. Verify system shows zero pressure on gauges before proceeding.
2. 2

   Access high-side AC hose connections
   Raise vehicle if necessary for access. The high-side hose runs from the condenser (front of vehicle) to the compressor. Remove any plastic covers or shields obstructing access to the hose fittings using trim removal tools. On the Bolt EUV, you may need to remove the front undertray for better access to the condenser connection.
3. 3

   Disconnect high-side hose at condenser
   Using a flare nut wrench, carefully loosen the AC line fitting at the condenser. Support the condenser connection with a backup wrench to prevent twisting the condenser tubes. Once loosened, unthread completely by hand and carefully separate the connection. Cap or plug the condenser port immediately to prevent moisture and debris entry. Remove and discard the old O-rings.
   ⚠A small amount of residual refrigerant or oil may escape when opening fittings. Wear eye protection.
4. 4

   Disconnect high-side hose at compressor
   Locate the high-side hose connection at the electric AC compressor. Using a flare nut wrench, loosen the AC line fitting while using a backup wrench on the compressor port. Unthread the fitting completely and separate the hose from the compressor. Cap or plug the compressor port immediately. Remove and discard the old O-rings.
5. 5

   Remove mounting brackets and extract hose
   The high-side hose is secured to the vehicle with mounting brackets. Remove the mounting bracket bolts and carefully route the old hose out of the engine bay, noting the exact routing path and any clips or guides. Take photos if needed for reinstallation reference.
   Torque spec

   Mounting Bracket Bolts24 Nm (18 lb-ft)
6. 6

   Prepare new high-side hose
   Unpack the new high-side AC hose assembly. Install new O-rings on both ends of the hose (4 total - 2 per connection point). Lightly coat all new O-rings with the appropriate PAG oil for your AC system. Ensure O-rings are properly seated in their grooves and not twisted or damaged.
7. 7

   Install new hose and route through engine bay
   Route the new high-side hose through the engine bay following the exact path of the original hose. Ensure the hose does not contact any sharp edges, hot surfaces, or moving components. Install the hose into any routing clips or guides that were used on the original hose.
8. 8

   Connect hose to compressor
   Remove the plug from the compressor port. Verify the port is clean and free of debris. Hand-thread the new hose fitting onto the compressor port, ensuring it threads smoothly without cross-threading. Once hand-tight, use a torque wrench and flare nut wrench to tighten the AC line fitting to specification. Hold the compressor port with a backup wrench during final tightening.
   Torque spec

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

   Connect hose to condenser
   Remove the plug from the condenser port. Verify the port is clean and free of debris. Hand-thread the new hose fitting onto the condenser port, ensuring smooth threading. Once hand-tight, use a torque wrench and flare nut wrench to tighten the AC line fitting to specification. Use a backup wrench on the condenser port during final tightening.
   Torque spec

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

    Secure mounting brackets
    Install all mounting brackets that secure the high-side hose to the vehicle structure. Ensure the hose has proper support and is not under tension or stress. Torque all mounting bracket bolts to specification.
    Torque spec

    Mounting Bracket Bolts24 Nm (18 lb-ft)
11. 11

    Evacuate AC system
    Connect the AC vacuum pump to the service ports. Evacuate the system to achieve a deep vacuum (minimum 29 inches Hg). Maintain vacuum for at least 30-45 minutes to remove all moisture and air from the system. Monitor vacuum gauge for any vacuum loss that would indicate a leak.
12. 12

    Recharge AC system
    Using the AC manifold gauges and charging equipment, recharge the system with the correct amount of R-1234yf refrigerant (refer to underhood label for capacity, typically around 1.4 lbs). Add refrigerant through the low-side port only with engine running and AC system on MAX/HIGH. Monitor pressures throughout charging process.

Reassembly

1. Reinstall any plastic covers, shields, or undertrays that were removed for access
2. Verify all AC line fittings are torqued to specification and show no signs of leakage
3. Ensure all tools and materials are removed from the engine bay

Verification

• Start the vehicle and turn AC system to MAX cooling with blower on HIGH
• Allow system to run for 5-10 minutes and verify cold air from vents
• Check all AC line connections for refrigerant leaks using electronic leak detector or soap solution
• Verify high-side pressure is appropriate for ambient temperature (typically 150-250 psi depending on conditions)
• Verify low-side pressure is appropriate (typically 25-45 psi)
• Check that compressor cycles on and off normally
• Inspect high-side hose routing for any contact with moving parts or excessive vibration
• Verify no unusual noises from AC system operation

More procedures for this vehicle