2004 Toyota Avalon heater core

Disconnect the negative battery cable.

CAUTION
After disconnecting the negative battery cable, wait for at least 1 1 / 2 minutes for the SRS to deplete its energy.

Drain the cooling system into a clean container for reuse.
Remove the air bag module and the steering wheel by performing the following procedure:

Place the front wheels in the straight-ahead position. At both sides of the steering wheel, remove the screw covers. Using a Torx socket, loosen the 2 air bag module-to-steering wheel Torx screws until the circumference ring catches on the screw case. Carefully, remove the air bag module and disconnect the electrical connector. Remove the steering wheel nut. Using a steering wheel puller, press the steering wheel from the steering column.

Remove the instrument panel by performing the following procedure:

Remove the front pillar garnishes and the door scuff plates. Remove the hood lock release lever and the cowl side trims. Remove the steering column covers and the combination switch. Remove the lower finish panel assembly and the instrument panel finish lower left side panel. Remove the fuse box bolt and the No. 2 heater-to-register duct. Remove the parking brake release lever and the No. 2 undercover. Remove the lower No. 2 finish panel. If equipped with a column shifter, disconnect the shift control cable from the shift lever housing; then, disconnect the shift control cable from the steering column cable bracket. Matchmark the steering column shaft and the control valve shaft. Remove the steering column shaft-to-intermediate shaft bolt. Remove the steering column-to-instrument panel nuts and remove the steering column assembly. Inside the glove compartment, pry out the glove compartment door finish plate. Pull out the air bag electrical connector and disconnect it. Remove the 3 glove compartment door-to-instrument panel nuts and the door. Remove the 4 glove compartment-to-instrument panel screws and the glove compartment; then, disconnect the glove box light connector. Remove the passenger-s side air bag module-to-instrument panel 2 bolts and 4 nuts. Carefully, remove the air bag module from the instrument panel. Remove the center cluster finish panel and the radio. Remove the heater control assembly. If equipped with a floor shifter, remove the upper console panel, the rear console box and the front console box. If equipped with a column shifter, remove the finish panel. Pry out the cluster finish panel. Remove the 6 cluster finish panel screws, the cluster finish panel assembly. Remove the 4 combination meter screws and the combination meter. Disconnect instrument panel electrical connectors. Remove the instrument panel-to-chassis nuts/bolts and the remove the instrument panel.

Remove the instrument panels No. 2 brace.
Disconnect the heater hoses from the heater core.
Remove the 2 heater pipes-to-heater core screws and clips; then, disconnect the heater pipes from the heater core.
Remove the heater core O-rings and discard them.
Remove the heater core from the heater housing.