Q: How to replace the compressor and receiver-drier in a Nissan Titan's air conditioning system?A: Whenever the compressor is replaced due to an internal failure, the receiver-drier should also be replaced. This component is integrated with the condenser. Removal involves having the air conditioning system refrigerant discharged by an air conditioning technician. The air intake duct and the air filter housing should be removed, followed by the drivebelt. The compressor clutch electrical connector should be disconnected. The left front wheel lug nuts should be loosened, the front of the vehicle raised and supported securely on jackstands, and the left front wheel removed. On Armada models equipped with a rear auto-leveling suspension, turn the ignition key to the OFF position before raising the vehicle. The engine splash shield beneath the front of the vehicle should be removed, along with the inner fender splash shield. The refrigerant lines from the compressor should be disconnected and all open fittings plugged to prevent entry of dirt and moisture. The compressor mounting fasteners should be removed, followed by the compressor itself. Installation involves following the directions with the compressor regarding the draining of excess oil prior to installation. Any refrigerant oil added must be compatible with R-134a refrigerant. The clutch may have to be transferred from the original compressor to the new one. Installation is the reverse of removal. Replace the O-rings with the appropriate type and lubricate them with refrigerant oil. Tighten the mounting and line fitting fasteners to the torque values. Finally, have the system evacuated, recharged and leak-tested by the shop that discharged it.