GM 89022546
Evaporator Core

The procedure for replacing the air conditioning Evaporator core begins with hvac module assembly removal. The insulation from the thermal expansion valve (TXV) should be discarded first after which you should remove the hvac line clamp screw and clamp. The procedure starts with removing txv to Evaporator bolts as well as the txv line bracket before extracting the txv from the Evaporator core by pulling it straight out. I disconnect all o-rings from their positions and separate the thermistor electrical connector from the hvac module retainer as well as the lh and auxiliary temperature actuator electrical connectors while moving the harness further away. Begin by removing the front duct through the retainers on the hvac module and unscrewing its case which enables you to separate the Evaporator core for removal. The installation process requires refrigerant oil addition while also requiring new Evaporator core seals. Install the Evaporator core into its place while matching every temperature and mode door to its designated slot inside the hvac module and avoid applying excessive pressure to the case halves. Apply alternative pressure of 1 n.m (8 lb in) when tightening the hvac module case screws after installing them between the case halves. Attach the front duct with proper retention of the installers then place the wire harness back in position and complete the connections by uniting the thermistor electrical connector with the lh and auxiliary temperature actuator electrical connectors. New o-rings go into both Evaporator core and txv lines before inserting air conditioning lines into the txv. You should position the txv onto the Evaporator core until it seates prior to installing the txv line bracket first and then install the txv to the Evaporator bolts using 3.5 n.m (31 lb in) torque. Place insulation over the lines and txv before reinstalling the hvac module when you first tighten the line clamp screw to 1 n.m (8 lb in) followed by proper installation of the screw.

Reattach the front duct, ensuring the retainers are engaged, reposition the wire harness, and connect the LH and auxiliary temperature actuator electrical connectors, followed by the thermistor electrical connector.

Reattach the front duct, ensuring the retainers are engaged.

Add refrigerant oil, install new evaporator core seals, and carefully place the evaporator core, ensuring all temperature and mode doors align.

Remove the HVAC line clamp screw and clamp, then the TXV to evaporator bolts and the TXV line bracket.

Install the front duct, ensuring the retainers are engaged.