Q: How is the expansion valve serviced on Nissan Sentra?
A: On 2012 models, the expansion valve is serviced with the Evaporator. First, have the refrigerant discharged at a dealer service department or an automotive air conditioning repair facility. Then, move aside the lower dash insulation to access the expansion valve pipe. On 2.5L engines, remove the cowl extension cover. Next, remove the refrigerant line-to-expansion valve bolts and disconnect the refrigerant lines. After that, remove the expansion valve mounting bolts and remove the expansion valve. Installation is the reverse of removal. Tighten the expansion valve bolts to the torque. Do not use old O-rings for the refrigerant lines; replace them with new ones and apply compressor oil to them before installation. Finally, have the system evacuated, charged and leak tested by the shop that discharged it.