A failing heater core will stop your car's heater from working, making for uncomfortable driving in winter months. Replacing a failing heater core in a 1997 Chevrolet Cavalier requires that most of the interior instrument panels be removed from the vehicle; the task is extensive, but most home mechanics can carry it out. Learn which panels to remove and the process for replacing the heater core before you attempt the job.
Drain the cooling system. Place a large oil drain container under the drain fitting on the bottom of the radiator. Turn the drain fitting with pliers until fluid is draining from the radiator. Tighten the drain fitting when the fluid is completely done draining from the radiator.
Disconnect the heater hoses at the heater core inlet and outlet on the engine side of the firewall. Loosen the hose clamps with a pair of pliers and pull the hoses away from the pipes.
Remove the lower dash insulators. Remove the screws holding the insulators under the glove box and under the steering wheel with a screwdriver, and pull them rearward to remove them.
Remove the instrument panel trim pad. Remove the center defroster grill retaining screw with a screwdriver and remove the grill. Remove the instrument panel end caps by hand and remove the panel trim pad retaining screws, located on both ends of the dash pad, with a screwdriver. Remove the trim panel retaining bolts inside the glove box with a ratchet wrench; remove the trim panel retaining screws inside the glove box with a screwdriver. Place a small pry bar between the instrument cluster and trim pad, and pry the pad away from the instrument cluster to detach the retaining clips. Pull the pad away from the instrument cluster and remove it from the vehicle.
Remove the instrument cluster and radio trim plate. Remove the two retaining screws at the left and right edges of the instrument cluster with a screwdriver, along with the retaining screw on the right side of the radio. Pull the trim plate away from the instrument cluster and radio and remove it.
Remove the heater core and evaporator trim panels, located in the center of the floor of the interior. Remove the four trim panel retaining screws with a screwdriver. Disengage the locking tab, separate the panels and remove them.
Remove the radio and climate control assembly. Remove the retaining screws holding the radio in place, using a screwdriver. Pull the radio forward and remove the stereo connection harness. Disconnect the antenna connection. Remove the radio. Remove the retaining screws holding the climate control assembly in place. Pull the assembly forward and disconnect the electrical connections at the back of the assembly. Remove the assembly.
Remove the steering wheel and steering column components. Disconnect the negative battery cable from the battery. Remove the retaining screws holding the steering column cover in place, using a screwdriver, and remove the cover. Remove the air bag module retaining screws behind the steering wheel with a screwdriver and carefully remove the air bag. Remove the steering wheel retaining nut with a ratchet wrench. Mark the steering wheel and shaft to ensure that you replace the steering wheel in the same position later. Place a steering wheel puller onto the steering column shaft and remove the steering wheel. Remove the retaining screws holding the windshield wiper switch and combination switch to the steering column, using a screwdriver. Pull the switches away from the steering column, disconnect the electrical connectors and remove the switches.
Remove the instrument panel. Remove the air duct retaining screws, glove-box light retaining screws and instrument panel retaining screws, using a screwdriver or a ratchet wrench. Pull the instrument panel away from the firewall and detach any electrical connections, then remove the panel from the vehicle.
Remove the heater core cover. Remove the core cover bolts from the front of the assembly and the two bolts from the middle and bottom of the assembly with a ratchet wrench. Pull the cover away from the assembly.
Remove the heater core. Remove the heater core clamp bolts with a ratchet wrench and remove the clamps. Lower the forward section of the heater core. Separate it from the heater core housing and remove it.
Install the new heater core. Slide the new core into position and replace the clamps and clamp bolts with a ratchet wrench.
Remove the heater core cover. Remove the core cover bolts from the front of the assembly and the two bolts from the middle and bottom of the assembly with a ratchet wrench. Pull the cover away from the assembly.
Install the heater core cover. Replace the core cover bolts to the front of the assembly and the two bolts to the middle and bottom of the assembly with a ratchet wrench.
Install the instrument panel. Place the instrument panel close to the firewall and attach any electrical connections. Push the instrument cluster to the firewall and replace the air duct retaining screws, the glove-box light retaining screws and the instrument panel retaining screws using a screwdriver or ratchet wrench.
Remove the steering wheel and steering column components. Attach the electrical connections to the combination switch and to the windshield wiper switch. Place the switches onto the steering column and install the retaining screws with a screwdriver. Place the steering wheel onto the shaft, aligning the marks made upon removal, and install the steering wheel retaining nut with a torque wrench to 30 foot-pounds. Put the air bag module in place and install the air bag module retaining screws with a screwdriver. Place the steering column cover over the steering column and replace the retaining screws with a screwdriver. Connect the negative battery cable to the battery.
Install the radio and climate control assembly. Put the climate control assembly in place and attach the electrical connections to the back of the assembly. Put the radio in place. Attach the antenna connection and stereo connection harness to the back of the radio. Install the retaining screws to the radio and climate control assembly with a screwdriver.
Install the heater core and evaporator trim panels, located in the center of the floor of the interior. Put the panels in place and engage the locking tab to join the two panels. Install the four trim panel retaining screws with a screwdriver.
Install the instrument cluster and radio trim plate. Put the panel in place and install the two retaining screws on the left and right edges of the instrument cluster, followed by the retaining screw on the right side of the radio, using a screwdriver.
Install the instrument panel trim pad. Put the trim panel in place and push down on the pad near the top of the instrument cluster to engage the retaining clips. Install the trim panel retaining bolts inside the glove box with a ratchet wrench and the trim panel retaining screws inside the glove box with a screwdriver. Install the retaining screws located at the ends of the instrument panel and push the two end cap covers in place. Place the center defroster grill and install the retaining screw with a screwdriver.
Install the lower dash insulators. Put the lower insulators in place and install the retaining screws with a screwdriver.
Connect the heater hoses at the heater core inlet and outlet on the engine side of the firewall. Tighten the hose clamps with pliers.
Refill the cooling system with the appropriate mix of antifreeze and water.
