So Fix it

Hot engine coolant goes through the tube of your heater core as part of a process that results in bringing heat to your vehicle. When this part needs to be removed, information on what to do before, during and after removal can be helpful.

Before Removal

On the passenger side of an automobile under the dash is a box that the heater core is in. You should notice the steel clamps that are screwed in to secure the heater core. You can take off the clamps and screws to free the core.

During Removal

Because water will be present in your heater core as you remove it, you should provide some form of cover for your vehicles carpet. You should be caul when taking out the heater core, as it may take a little elbow grease to pull it loose.

After Removal

After you have taken the heater core out, you can replace it with a new one and check the results. Once everything is installed, filling the system with water will allow you to perform a leak check. The heat should be turned up full blast while checking for signs of leaks.

A heater core in a vehicle is a radiator which contains hot coolant from the engine. The coolant passes through the heater core when the heater is turned on, and releases heat inside the vehicle. The heater core in a 1991 Eagle Premier is part of the heating and air conditioning unit. This requires you to remove the heating and air conditioning unit prior to installing the heater core.

Instructions

1

Disconnect the cable from the negative battery terminal with a socket wrench. Drain the coolant from the radiator, and store it for later use.

2

Discharge the rigerant in the air conditioning system with an approved rigerant recycling machine. This step requires a licensed mechanic.

3

Remove the lower trim cover of the instrument panel with a socket wrench, and disconnect the support rod for the instrument panel. Remove the screw that attaches the electrical wiring harness for the steering column to the instrument panel bulkhead.

4

Disconnect the automatic shift cable from the drive lever with a pair of pliers. Pull the sleeve on the steering column down to expose the universal joint. Mark the steering column shaft and the intermediate shaft so you can align the two shafts later. Remove the mounting bolt connecting the two shafts.

5

Disconnect the mounting bolts on the steering column with a socket wrench, and remove the steering column from the instrument panel. Separate the steering column shaft and intermediate shaft, and remove them from the vehicle. Detach the defroster grille from the the instrument panel.

6

Remove the screws that attach the parking brake handle with a socket wrench, and lower the handle. Detach the ashtray and electrical connector for the cigarette lighter. Disconnect the mounting bolts that attach the instrument panel to the floor. Detach the interior temperature sensor and duct extension from the floor of the vehicle.

7

Detach the hoses from the heater core, and unplug the electrical connector from the coolant level switch. Disconnect the reservoir for the coolant from the heater unit. Detach the electrical connector for the blower motor, and remove the vacuum lines from the heater unit. Detach the rigerant lines from the dash panel.

8

Remove the retaining nuts from the heater unit with a socket wrench, and pull the heater unit toward the rear of the vehicle to remove it. Release the tabs on the heater unit housing, and remove the heater core. Push the new heater core into the housing so that the tabs snap into place. Ensure that the gaskets on the heater housing form a tight seal.

9

Perform steps three through seven in reverse order to install the heater unit into the vehicle. Align the steering column shaft and the intermediate shaft according to the marks you made in step four. Tighten the bolts that fasten the steering column to the instrument panel to 35 foot-pounds with a torque wrench.

10

Recharge the air conditioning system with rigerant. This step requires a qualified mechanic.

11

Attach the cable to the negative battery terminal with a socket wrench. Refill the radiator with coolant, and check for any coolant leaks.

When your engine produces hot coolant, it flows through and heats up the core. The core then heats the air for your vehicle. When this part needs replacement, information and instructions on doing so can be beneficial to vehicle owners.

Remove

The top part of the dash and its lower panel have to be removed to access the heater core. The plastic box over the heater core will need to be removed as well.

Replace

A screwed on clamp made of steel holds the heater core in place. After removing the screws and the clamp, gently pull the heater core out, as it will contain some water. Covering your vehicles carpet with some type of sheeting is recommended.

Time Frame

The location of a heater core varies by vehicle type. The heater core has a location thats difficult to access on some vehicles. The time it takes to replace a heater can go well above six hours.

If you have allowed your Chevy Blazer time to warm up but still do not feel any heat in the passenger compartment there is a good chance that you have a faulty heater core. Because the heater core is located against the firewall, many mechanics charge quite a bit of labor for this repair. If you want to save the majority of the repair estimate, this is a job that you can complete yourself in about an hour.

Instructions

1

Disconnect the battery cable from the negative terminal on your Blazers battery. You need to do this any time you are completing a repair on your vehicle to reduce the chance of receiving an electrical shock.

2

Place a bucket under the radiator and drain the coolant from the cooling system. Typically, the drain plug is located at the bottom center of the radiator.

3

Remove the coolant hoses leading from the heater core to the engine. These are on the engine compartment side of the heater core. Plug the tubes of the heater core with a shop rag to reduce the chances of spilling coolant inside the vehicle when you remove the heater core.

4

Remove the heater core case located inside the passenger compartment. This case is located under the dashboard, just to the right of center of the vehicle. To do this, turn the screws connecting the heater core cover to the cowl counterclockwise and remove them.

5

Remove the support brackets from the heater core and remove the core from the passenger compartment side of the firewall.

6

Install the new heater core into the firewall. Be caul when you insert the tubes through the firewall so you dont bend them.

7

Install the support brackets and the heater core cover. Replace all of the retaining screws and turn them clockwise to secure.

8

Connect all hoses leading from the engine to the heater core inside the engine comparment, fill the radiator with coolant and reconnect the negative battery terminal.