Q: How to remove and clean the evaporator core and A/C Expansion Valve in a Toyota Land Cruiser's air conditioning system?
A: Have the air conditioning system discharged. Disconnect the negative cable from the battery. If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery. Remove the glove compartment assembly. Disconnect the air conditioning lines at the firewall, use a back-up wrench so as not to damage the fittings. Cap the open fittings after disassembly to prevent the entry of air or dirt. On 1FZ-FE engines, remove the ECM. Remove nuts and screws retaining the evaporator unit to the firewall and pull the unit out of the vehicle. With the evaporator unit on the bench, remove the screws and clips and separate the top and bottom halves of the case and pull out the evaporator. Pull the thermistor sensor probe from the evaporator core and unbolt the expansion valve and the two short refrigerant lines. The evaporator core can be cleaned with a "fin comb" and blown off with compressed air. If the evaporator core is replaced with a new unit, add 1.4 ounces of new refrigerant oil of the correct type (R-12 vs. R-134a) to the system. The remainder of the installation is the reverse of the removal process. Be sure to use new 0-rings, and new gaskets on the expansion valve. Have the system evacuated, charged and leak tested by the shop that discharged it.