GM 89019127
Evaporator Core

The HVAC module assembly removal stands as the first step when replacing the air conditioning evaporator core. The next step is to remove the screws which connect the recirculation housing to the HVAC module assembly before extracting the recirculation housing. You should now remove all screws which attach the mode actuator to the HVAC module assembly before extracting the mode actuator from its position. Extract the TXV by unfastening its bolts from the evaporator core and discard the old seal rings from this core before removing the TXV. A small chisel should be used to remove the heat stakes after you unscrew the upper case screws connecting HVAC module assembly parts to lower case components. The HVAC module assembly case must be separated first before removing its evaporator core. Before installing the evaporator core into the HVAC module assembly lower case, users must apply refrigerant oil as well as install new side and upper seals and two lower seals. Drill into the dimples on the upper case using a 7/32 in (5.5 mm) drill bit inserted from inside. Then join together the upper and lower HVAC module assembly cases in proper alignment. Secure the upper case to the lower case by installing screws achieving 1.5 N.m (13 lb in) of torque while adding new screws to the predrilled holes near the heat stakes whose torque should be set to 1.5 N.m (13 lb in). Fasten the mode actuator with screws which need to be tightened to 1.5 N.m (13 lb in). Fasten the recirculation housing to the HVAC module assembly through screws which should be tightened to 1.5 N.m (13 lb in). New sealing washers go onto the evaporator core before mounting the TXV to it while using bolts with a torque of 7 N.m (62 lb in). Finish the procedure with HVAC module assembly reinstallation.

The service procedure begins with HVAC module assembly removal then continues with recirculation housing screws followed by detaching the housing from the assembly. First unfasten the screws that keep the mode actuator on the HVAC module assembly then disconnect the mode actuator. Start with removing the bolts which secure the TXV to the evaporator core before separating the TXV itself while discarding any old seal rings present in the evaporator core. You must first separate the HVAC module assembly upper case from its lower case position before using a small chisel to eliminate the heat stakes. The HVAC module assembly case must be separated from the rest before removing the evaporator core. Tables with refrigerant oil rates for replacing evaporators can be used to determine appropriate oil addition. The HVAC module assembly lower case should have the new side, upper, and two lower seals installed to the evaporator core before placing it in position. Drill the dimples near the heat stakes from the upper case interior while using a 5.5 mm (7/32 in) drill bit then join together the upper and lower HVAC module assembly case and replace the upper case screws to lower case while tightening to 1.5 N.m (13 lb in). Drive in new screws through holes that are next to the heat stakes following a 1.5 N.m (13 lb in) torque specification. Secure the mode actuator with screws that need to be tightened to 1.5 N.m (13 lb in). Screw and tighten the HVAC recirculation housing to the assembly until it reaches 1.5 N.m (13 lb in). Sealing washers should be replaced on both the evaporator core and the TXV before securing with bolts whose torque must be set to 7 N.m (62 lb in). Complete the installation with reinstallation of the HVAC module assembly.

Remove the screws securing the mode actuator and take out the mode actuator from the HVAC module assembly.

Add refrigerant oil according to system capacity information.

Disconnect the mode actuator electrical connector and remove the mode actuator.

Install new side, upper, and lower seals on the evaporator core before placing it into the HVAC module assembly lower case.