Replace the heater hoses connecting the engine to the heater core, including inlet and outlet hoses for the HVAC system on the 2018-2024 Toyota Camry 2.5L I4.

Warnings

Tools required

Parts

• Heater inlet hose × 1 — Use OEM specification
• Heater outlet hose × 1 — Use OEM specification
• Hose clamps × 4 — Spring or worm-drive type as original

Fluids

• Toyota Super Long Life Coolant (Pink) — 2 qt

Preparation

1. Ensure engine is completely cold (has not run for at least 2 hours)
2. Park vehicle on level ground and engage parking brake
3. Place drain pan under radiator drain plug
4. Remove engine splash shield if equipped to access drain plug
5. Open hood and locate heater hoses at firewall and engine connections

Procedure

1. 1

   Drain cooling system
   Remove the radiator cap slowly to release any residual pressure. Locate the radiator drain plug at the bottom passenger side of the radiator. Open the drain plug and drain approximately 2 quarts of coolant into the drain pan. This is sufficient to lower coolant level below heater hose connections.
   ⚠Even when cool, some pressure may remain. Open radiator cap slowly with a rag to release pressure gradually.
   Torque spec

   Coolant Drain Plug15 Nm (11 lb-ft)
2. 2

   Access heater hoses at firewall
   Locate the two heater hoses at the firewall on the passenger side of the engine bay. These hoses connect the engine coolant passages to the heater core inside the cabin. Identify the inlet hose (from engine to heater core) and outlet hose (from heater core back to engine). Take photos for reference during reassembly.
3. 3

   Remove firewall-side hose clamps
   Using hose clamp pliers or a flathead screwdriver, loosen and slide back the hose clamps at the firewall heater core connections. If using spring clamps, compress the tabs and slide the clamps back along the hoses. If using worm-drive clamps, loosen the screw and slide clamps away from connection points. Be prepared for coolant spillage.
4. 4

   Disconnect hoses at firewall
   Twist the hoses gently to break the seal, then pull firmly to remove from the heater core pipes at the firewall. If hoses are stuck due to age, use a gentle rocking motion while pulling. Allow residual coolant to drain into your drain pan or towels. Cap or plug the heater core pipes with suitable plugs or tape to prevent debris entry.
5. 5

   Access engine-side connections
   Follow the heater hoses from the firewall to their connection points on the engine. The inlet hose typically connects to the engine coolant outlet housing near the thermostat. The outlet hose connects to the water pump or engine block. Remove any wire harness clips or brackets holding the hoses in place.
6. 6

   Remove engine-side hose clamps
   Loosen and slide back the hose clamps at the engine connections using the same method as at the firewall. Note the orientation and position of clamps for reinstallation. Keep clamps organized if reusing, or prepare new clamps for installation.
7. 7

   Remove old heater hoses
   Twist and pull the hoses to disconnect them from the engine fittings. If hoses are degraded or stuck, carefully cut them away with a utility knife, taking extreme care not to damage the metal fittings underneath. Clean the engine and firewall pipe connections with a shop towel to remove old coolant residue and debris.
8. 8

   Inspect fittings and prepare new hoses
   Inspect all metal pipe fittings at the engine and firewall for corrosion, cracks, or damage. Replace any damaged fittings before proceeding. Compare new hoses to old hoses to verify correct part numbers and routing. Slide new hose clamps onto the new hoses before installation.
9. 9

   Install new hoses at engine
   Route the new heater hoses along the same path as the originals. Connect the inlet hose to the engine coolant outlet housing and the outlet hose to its engine connection point. Push hoses fully onto fittings until they bottom out. Position hose clamps approximately 1/4 inch from the end of each hose, over the bead on the fitting.
10. 10

    Tighten engine-side clamps
    Tighten the hose clamps at the engine connections. If using worm-drive clamps, tighten to the specified torque. Ensure clamps are positioned over the raised bead on the fittings. Verify hoses are fully seated and cannot be pulled off by hand.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
11. 11

    Connect hoses at firewall
    Route the hoses to the firewall heater core connections. Remove any temporary plugs from the heater core pipes. Push the hoses fully onto the heater core pipes until they seat completely. Ensure proper routing with no kinks or sharp bends that could restrict coolant flow.
12. 12

    Tighten firewall-side clamps
    Position the hose clamps over the heater core pipe beads and tighten to specification. Double-check that all four hose connections are secure and clamps are properly positioned. Reinstall any wire harness clips or brackets that were removed.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
13. 13

    Close drain plug and refill coolant
    Close and tighten the radiator drain plug to specification. Remove the radiator cap and begin slowly filling the cooling system with Toyota Super Long Life Coolant (Pink) mixed to the proper 50/50 concentration. Fill until coolant is visible at the radiator neck. Squeeze accessible hoses to help purge air bubbles.
    Torque spec

    Coolant Drain Plug15 Nm (11 lb-ft)
14. 14

    Bleed cooling system and verify
    With the radiator cap off, start the engine and allow it to idle. Turn the heater to maximum temperature and fan speed. As the engine warms, the thermostat will open and coolant level will drop. Continue adding coolant as needed. Watch for coolant circulation in the radiator. Run until engine reaches normal operating temperature and cooling fans cycle on. Monitor all heater hose connections for leaks.
    ⚠Keep hands away from moving fan and hot components while engine is running.
15. 15

    Final fill and pressure test
    Once engine is at operating temperature and all air is purged, top off the radiator to the proper level. Install the radiator cap securely. Check the coolant reservoir and fill to the FULL mark. Allow engine to idle for 5 more minutes, then shut off. After engine cools, recheck coolant level and inspect all connections for leaks. Reinstall engine splash shield if removed.

Reassembly

1. Verify all hose clamps are tightened to specification and properly positioned
2. Ensure no tools or rags are left in the engine bay
3. Reinstall any engine covers or splash shields that were removed
4. Properly dispose of old coolant according to local regulations

Verification

• Start engine and verify heat output from cabin heater at maximum temperature setting
• Check for coolant leaks at all four heater hose connections with engine at operating temperature
• Verify coolant level is at FULL mark in reservoir after test drive
• Monitor coolant temperature gauge during test drive to ensure normal operating temperature
• Recheck all connections after 24 hours of driving and top off coolant if necessary

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