Replace the AC hose assembly on a 2014-2019 Toyota Corolla 1.8L, including refrigerant recovery, hose removal, installation with new O-rings, and system recharge.

Warnings

Tools required

Parts

• AC hose assembly (specify which hose: suction, discharge, or liquid line) × 1 — Use OEM specification
• AC O-ring kit × 1 — Use OEM specification
• R-134a refrigerant × 1 — Approximately 18-20 oz per system capacity
• PAG oil (ND-11) × 1 — Use OEM specification

Preparation

1. Ensure engine is cold and vehicle is parked on level ground
2. Verify which AC hose assembly requires replacement (suction line, discharge line, or liquid line)
3. Gather AC recovery equipment and ensure refrigerant storage tank has adequate capacity
4. Disconnect negative battery terminal and wait 90 seconds for airbag system discharge
5. Remove engine under cover if accessing lines from below

Procedure

1. 1

   Recover refrigerant from AC system
   Connect AC recovery machine to service ports on suction and discharge lines. Follow recovery machine instructions to completely remove all refrigerant from the system. Verify system pressure reads 0 psi on manifold gauges before proceeding. Record amount of refrigerant recovered for recharge reference.
2. 2

   Access AC hose connections
   For suction and liquid line: Remove engine cover by pulling upward on clips. For discharge line from compressor: May require removing splash shield from wheel well. Identify the connection points of the hose assembly being replaced. Clean area around fittings with shop towels to prevent debris entry.
3. 3

   Disconnect AC hose at compressor end
   Using appropriate flare nut wrench, carefully loosen the AC line fitting at the compressor. Hold the compressor port stationary with a backup wrench if necessary to prevent component damage. Once loose, remove fitting completely by hand. Immediately cap open ports with plugs or tape to prevent moisture and debris entry. Remove and discard old O-rings.
4. 4

   Disconnect AC hose at condenser/evaporator end
   Locate the opposite end connection point (condenser for discharge/liquid lines, or evaporator connections for suction line). Use flare nut wrench to loosen fitting. For lines running to firewall connections, access may require working from engine bay and/or removing glove box for evaporator connections. Remove fitting and immediately cap open ports. Remove and discard old O-rings.
5. 5

   Remove AC hose assembly mounting brackets
   Locate and remove any mounting bolts or clips securing the hose assembly to the engine bay or chassis. Typical locations include brackets near the strut tower and along the firewall. Note routing path and bracket positions for reinstallation.
   Torque spec

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

   Extract old AC hose assembly
   Carefully maneuver the old hose assembly out of the engine bay, noting exact routing path, orientation, and clearances from other components. Take photos if necessary for reference during installation. Inspect removed hose for failure point to confirm replacement is addressing the correct component.
7. 7

   Prepare new AC hose assembly
   Unpack new AC hose assembly and verify it matches the old part. Install new O-rings on all fittings (do not reuse old O-rings). Lightly coat new O-rings with fresh PAG oil (ND-11) to ensure proper sealing and prevent damage during installation. Add approximately 1-2 oz of PAG oil into open hose end to replace oil lost with old hose.
8. 8

   Route new AC hose assembly
   Following the routing path documented during removal, carefully position the new hose assembly in the engine bay. Ensure hose does not contact sharp edges, hot components (exhaust manifold), or moving parts (drive belt, cooling fans). Verify adequate clearance and natural bend radius without kinks or excessive tension.
9. 9

   Install mounting brackets
   Secure the AC hose assembly to mounting brackets. Install bolts hand-tight first to allow for positioning adjustment. Once all brackets are engaged and hose routing is verified correct, torque mounting bolts to specification.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
10. 10

    Connect AC hose at compressor
    Remove protective caps from compressor port and new hose fitting. Verify O-ring is properly seated in fitting groove and coated with PAG oil. Thread fitting onto compressor port by hand until snug, ensuring straight alignment to prevent cross-threading. Using torque wrench and flare nut wrench, tighten to specification.
    Torque spec

    AC Line Fittings20 Nm (15 lb-ft)
11. 11

    Connect AC hose at condenser/evaporator end
    Remove protective caps from component port and hose fitting. Verify O-ring condition and PAG oil coating. Hand-thread fitting until snug, checking for proper alignment. Torque to specification using appropriate wrench.
    Torque spec

    AC Line Fittings20 Nm (15 lb-ft)
12. 12

    Evacuate AC system
    Connect vacuum pump to AC service ports. Run vacuum pump for minimum 45 minutes to achieve deep vacuum (29+ inches Hg). Close manifold valves and shut off pump. Monitor vacuum gauge for 10 minutes - system should hold vacuum without pressure rise, indicating no leaks. If vacuum drops, locate and repair leak before proceeding.
13. 13

    Recharge AC system
    With system under vacuum, connect refrigerant supply to manifold gauges. Charge system with R-134a refrigerant to manufacturer specification (approximately 18-20 oz total, adjusted for amount recovered and PAG oil added). Charge liquid refrigerant into low side with engine off, then start engine and run AC on MAX/recirculate to complete charge via low side as vapor. Monitor gauge pressures during charging.
14. 14

    Leak test system
    With system fully charged and pressurized, use electronic leak detector or approved soap solution to check all new connections for leaks. Pay special attention to both fittings on the new hose assembly. Check manifold gauge readings match specifications (typically 25-35 psi low side, 200-250 psi high side at idle with ambient temperature 70-80°F).

Reassembly

1. Reinstall engine under cover or wheel well splash shield if removed
2. Reinstall engine cover, pressing firmly until clips engage
3. Reconnect negative battery terminal
4. Reset clock and radio presets as needed

Verification

• Start engine and set AC to MAX cool with fan on high and recirculate mode active
• Verify cold air output from vents reaches 40-50°F within 2-3 minutes
• Check compressor clutch engages and cycles normally without unusual noises
• Verify no refrigerant leaks at new hose connections using leak detector
• Confirm AC system pressures remain stable during 10-minute test run
• Inspect new hose assembly routing for proper clearance during engine operation
• Test AC performance under various operating conditions (idle, cruise, MAX AC, economy mode)

More procedures for this vehicle