GM 15221028
Expansion Valve

The first step for replacing a thermal expansion valve (TXV) begins with the recovery of a/c system refrigerant. Start by moving heater hoses into a more clear position and proceed to disconnect the vacuum hose from the Brake Booster before relocating it. First detach the Evaporator outlet tube to txv nut before removing the Evaporator outlet tube from the txv and disconnect it from the Evaporator inlet tube. The procedure to prevent contamination requires immediate capping or taping off the a/c refrigerant tubes after removing all their sealing washers. Begin by removing txv to Evaporator bolts before extracting the txv out of the Evaporator core while throwing away the sealing washers then capping or taping the Evaporator core. Run a cap or tape off the Evaporator core before installing new sealing washers then secure the txv to the Evaporator core with txv to Evaporator bolts which should be fastened to 3.2 n.m (28 lb in). You must remove the cap or tape from the a/c refrigerant tubes before putting sealing washers on them and joining the Evaporator inlet tube with the Evaporator outlet tube then connecting the tubes to the txv and ending with installation of the Evaporator outlet tube nut which must be tightened to 16 n.m (12 lb ft). After connecting the vacuum hose to the Brake Booster the installer should reposition the heater hoses before conducting the evacuation and recharging of the a/c system and testing all fittings with the halogen leak detector (J 39400-A).

The first step for thermal expansion valve (TXV) replacement begins with proper procedures to recover refrigerant from the a/c system. Circumvent heat hoses first then remove the vacuum hose from the Brake Booster before its repositioning. Begin by loosening the Evaporator outlet tube to txv nut before detaching the Evaporator outlet tube from the txv as well as from the Evaporator inlet tube. The technician should immediately discard the sealing washers and cap or apply tape over the a/c refrigerant tubes to avoid contamination. Take out the txv from the Evaporator core by executing the txv to Evaporator bolt removal and discard both sealing washers before capping or taping off the Evaporator core. Place new sealing washers on the Evaporator core and secure the txv to the core with txv to Evaporator bolts that should be tightened to 3.2 n.m (28 lb in). First remove the tape or cap from the a/c refrigerant tubes then install sealing washers to each tube before connecting the Evaporator outlet to the Evaporator inlet then proceed with connecting the Evaporator tubes to the txv. Tighten the Evaporator outlet tube nut to 16 n.m (12 lb ft). The vacuum hose should be reconnected to the Brake Booster before realigning the heater hoses to perform an a/c system evacuation and recharge process. The last step includes conducting a leak test of component fittings using the halogen leak detector (J 39400-A).

Remove the TXV to evaporator bolts and take out the TXV from the evaporator core, discarding the sealing washers again and capping or taping off the evaporator core.

Remove the evaporator outlet tube to TXV nut and disconnect the evaporator outlet tube from the TXV and the evaporator inlet tube.

Remove the cap or tape from the evaporator core and clean the sealing surfaces with a lint-free clean, dry cloth.

Install new sealing washers.

Detach the A/C lines from the auxiliary TXV, ensuring to cap or tape the open A/C refrigerant lines immediately to prevent contamination.

Recover the refrigerant from the A/C system.

Disconnect the auxiliary TXV solenoid electrical connector.