GM 88956885
Heater Core

Draining the cooling system should be the first step when replacing the Heater Core in the auxiliary system. Finally raise up the vehicle while providing support. The work starts with disconnecting heater hoses using quick disconnects before the vehicle lowers. You need to start by taking off the left side rear quarter lower trim panel then unfasten both the heater pipe bracket retaining screw and bracket before removing the heater pipe block fitting bolt to disconnect the heater pipe block fitting from the Heater Core. The removal of heater pipe block fitting bolt allows you to gently push heater pipes downward to separate the heater pipe block fitting from the Heater Core. Tightly pull the Heater Core straight out from the hvac module by removing the retaining screws while maintaining attention to cooling fin safety. To install the Heater Core position it directly within the hvac module followed by screwing the retaining clips which should be secured at 1.6 n.m (14 lb in). Position the heater pipe block fitting correctly onto the Heater Core then install and tightly screw the heater pipe block fitting retaining bolt to 16 n.m (12 lb ft). Begin by installing the heater pipe bracket and its retaining screw and tighten them to 1.6 n.m (14 lb in). After that, reinstall the left side rear quarter lower trim panel. Support the vehicle before reconnecting the heater hose fasteners and complete the process by lowering the vehicle and filling the cooling system.

Disconnect the auxiliary heater hoses from the auxiliary heater core pipes and lower the vehicle.

Install the heater core pipe retaining clamp screw and tighten it to 1.6 N.m (14 lb in).