Heater Core Replacement 93 Seville STS

[TRB482000]

Is there anyone out there that has some advice or tips for replacing the heater core in a 93 Seville STS?

Thanks.

[Cadillac Jim]

The 1997 factory service manual, page 1B-27, makes it look simple:

Remove or Disconnect

1. Negative battery cable.
2. Partially drain coolant. Refer to Draining and Refilling in Egine Cooling.
3. Instrument panel compartment.
4. Right sound insulator.
5. Heater and A/C programmer.
6. Heater core cover.
7. Inlet and outlet heater hoses from heater core.
8. Heater retaining screws.
9. Heater core.

Zingers include room to work; you might consider removing the passenger seat. The heater hoses are in the engine compartment and are difficult to reach, and removing them can be very difficult. You might consider pulling the surge tank to get access, and replacing the hoses to the heater core with new ones. This will let you slit the hoses and pry them off with a screwdriver.

Installation is almost the reverse of these steps:

Install or Connect

1. Heater core to heater case, securing with two screws.
2. Inlet and outlet heater hoses to heater core.
3. Heater core cover.
4. Heater and A/C programmer.
5. Instrument panel compartment.
6. Right sound insulator.
7. Negative battery cable.
8. Refill cooling system. Refer to Draining and Refilling in Engine Cooling.
9. Adjust the air mix valve.

Have a nice day.

[Dan]

Yes, the hoses to the heater core are almost IMPOSSIBLE to get to. They are behind the shock tower. You'll need a long screwdriver or 1/4 drive set, and a lot patience. Maybe it's easier if you remove them from the inside of the car. I don't know if this is possible or not. A quick fix would be to just bypass the heater core if it is leaking.