Heater Core Case: Service and Repair
REPLACEMENT1. Recover the refrigerant with a recovery/recycling/charging station.
2. When the engine is cool, drain the engine coolant from the radiator.
3. Disconnect the negative cable from the battery.
4. Remove the bolts (A) and the expansion valve (B) from the evaporator core.
Plug or cap the lines immediately after disconnecting them to avoid moisture and dust contamination.
5. Disconnect the inlet (C) and outlet (D) heater hoses from the heater unit.
Engine coolant will run out when the hoses are disconnected; drain it into a clean drip pan. Be sure not to let coolant spill on electrical parts or painted surfaces. If any coolant spills, rinse it off immediately.
6. Remove the crash pad.
7. Disconnect the connectors (A) from the temp. actuator, the mode actuator and the thermistor, then remove the mounting nut (B), the mounting bolts (C) and heater & evaporator unit (D).
8. Remove the self applying screws and the upper bracket (A), the side bracket(B).
Be careful not to bend the inlet and outlet pipes during heater core(C) removal, and pull out the heater core.
9. Install the heater core in the reverse order of removal.
10. Install in the reverse order of removal, and note these items:
- If you're installing a new evaporator, add refrigerant oil (FD46XG).
- Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them. Be sure to use the right O-rings for R-134a to avoid leakage.
- Immediately after using the oil, replace the cap on the container, and seal it to avoid moisture absorption.
- Do not spill the refrigerant oil on the vehicle; it may damage the paint; if the refrigerant oil contacts the paint, wash it off immediately.
- Apply sealant to the grommets.
- Make sure that there is no air leakage. Charge the system, and test its performance.
- Do not interchange the inlet and outlet heater hoses and install the hose clamps securely.
- Refill the cooling system with engine coolant.