OEM 2009 Cadillac STS Evaporator

2009 Cadillac STS Parts Questions & Experts Answers

• Q: How to replace the air conditioning evaporator core on 2009 Cadillac STS?

  A: The replacement of an air conditioning Evaporator core starts with hvac module assembly removal. The first step requires discarding insulation material surrounding the thermal expansion valve (TXV) then removing the hvac line clamp screw and clamp. First remove the txv to Evaporator bolts before deleting the txv line bracket and ultimately pull the txv out from its position in the Evaporator core to separate it from a/c lines by pulling them straight out. You must discard all o-rings while disconnecting the thermistor electrical connector, the lv and auxiliary temperature actuator electrical connectors from the hvac module retainer to reposition the harness. The front duct on the hvac module needs retainers removed to access the case screws and separate its components for taking out the Evaporator core. Place refrigerant oil on the Evaporator during installation and use new seals on the core while taking care not to forcefully put the core into the hvac module to protect the thermistor. Insert the Evaporator core into the hvac module while aligning its temperature and mode doors correctly before joining the case halves without excessive force. Fasten the case with screws at 1 nm (8 lb in) before placing the front duct into position with retainers correctly aligned. The wire harness must be repositioned before connecting the lh and auxiliary temperature actuator electrical connectors as well as the thermistor electrical connector to the hvac module retainer. New o-rings should be installed to both Evaporator lines and txv lines followed by connecting a/c lines into the txv. Fit the txv precisely against the Evaporator core until it reaches full seating then install the txv line bracket after securing the txv to Evaporator bolts that require 3.5 nm (31 lb in) torque. To finish install the hvac line clamp and screw then tighten both pieces to 1 nm (8 lb in). Reinstall insulation on lines and txv before putting back the hvac module.