GM 10318613
Expansion Valve

The first task to replace the A/C Expansion Valve (TXV) in the air conditioning system involves recovering the refrigerant from the a/c system. The procedure requires workers to remove both left wiper arm linkage nuts followed by relocating the linkage for better access and heater hoses to create clearance space. Transfer the Brake Booster vacuum hose to a different location before doing so. First untighten the Evaporator outlet line to txv nut before disconnecting both Evaporator outlet and inlet lines from the A/C Expansion Valve device then disconnecting the Evaporator outlet line from the Evaporator inlet line. Sealing washers need replacement before taping or capping the opened a/c refrigerant lines to stop contamination. Drain the Evaporator core by removing both A/C Expansion Valve to Evaporator bolts and extracting the A/C Expansion Valve device while discarding the sealing washers. The installation procedure requires removing tape or caps from the Evaporator core followed by using a lint-free cleaning cloth to clean both sealing surfaces. Install the new sealing washers onto the Evaporator core until they reach their correct position before fitting the A/C Expansion Valve to the core while employing correct fasteners that match the application part number specifications. Schedule 4-40 bolts that secure the A/C Expansion Valve to Evaporator receive a torques of 3.2 nm (28 lb in). Uncover the a/c lines while cleaning their sealing surfaces before installing the sealing washers onto each line until properly seated. After connecting the Evaporator inlet line to the Evaporator outlet line it is necessary to join the Evaporator outlet and inlet lines to the A/C Expansion Valve. Secure the Evaporator outlet line nut at 16 nm (12 lb ft) and reattach the heater hoses along with reconnecting the vacuum hose to the Brake Booster. Fitting the left wiper arm linkage requires tightening its nuts to 5 nm using 44 lb in torque. The a/c system evacuation process starts with charging then performing a halogen leak detector j 39400-a test on all fittings.

Evacuate and recharge the A/C system, and perform a leak test on the fittings of the component using the Halogen Leak Detector (J 39400-A).

Remove the bolt from the auxiliary TXV line block fitting, followed by the A/C lines from the auxiliary TXV, discarding the sealing washers.

Take out the auxiliary TXV line clamp screws and the clamp.

Slide the new sealing washers onto the evaporator lines until seated.