GM 15211569
Heater Core

A replacement of Heater Core begins with draining the cooling system fluids. Take out the wiper module before disconnecting the Brake Booster Vacuum Hose and moving its position. Then remove the air cleaner outlet duct and the transmission fluid filler tube. The ge-47622 hose clamp pliers (GE-47622) will enable you to detach both heater hose clamps connected to the Heater Core and then remove the heater hoses but secure caps to the Heater Core inlet and outlet to avoid coolant leakage. The heater outlet duct removal process starts by removing the right and left instrument panel (I/P) insulators alongside the center floor air outlet screws together with the heater outlet duct. Remove the i/p harness to Heater Core cover tie strap before removing the screws retaining the Heater Core cover and finally taking off the cover itself. First extract the Heater Core pipe retaining screw and remove the Heater Core out from the hvac module. Place the Heater Core inside the hvac module case followed by installation of the Heater Core pipe retaining clamp screw then proceed to tighten it to 0.9 n.m (8 lb in). Reinstall the Heater Core cover together with its retaining screws while tightening these to 0.9 n.m (8 lb in). The heater outlet duct screws should be installed next while securing the i/p harness to the Heater Core cover tie strap and after that install the center floor air outlet. The installation process ends with heater hose clamping using ge-47622 while reinstalling both left and right i/p insulators. The process ends by installing the transmission fluid filler tube and the air cleaner outlet duct and the Brake Booster Vacuum Hose while also reconnecting the wiper module before filling the coolant.

Disconnect the throttle and cruise control cables from the TBI mounting bracket to avoid bending the cable housings.

Remove the IP harness to heater core cover tie strap, followed by the screws retaining the heater core cover, and then take off the heater core cover.

Remove the transmission fluid filler tube.

Remove the auxiliary HVAC module.

Remove the left wiper arm linkage nuts and reposition the linkage for access.

First, drain the cooling system and then raise and support the vehicle.

Remove the heater core cover.

Place the heater core back into the HVAC module, ensuring the correct fasteners are used in the correct locations, and install the heater core pipe retaining clamp screw, tightening it to 1.6 Nm (14 lb in).