Before dealing with Z4 models, you must have an experienced BMW dealer or specialist service remove the refrigerant. First strip away the heater assembly, and then remove the adapter plate attached to the heater assembly. Unhook the cover retainers from the evaporator, then unscrew the upper cover screw and take out its holding clips before you remove the whole top cover. Free the evaporator by unscrewing mounting screws on both ends, then lift it away from the heater assembly. Renewing your vehicle goes back by the steps used to install, fixing any refrigerant shortages and filling up the coolant tank. Be sure to empty the remaining refrigerant from the engine before you can unscrew the connecting bolts from the line fittings and place where the hoses attach to the firewall. Unplug the air conditioning tubes, adapter plate, and steer the rubber seal inside the firewall outside. Unscrew expansion valve mounting bolts, put fresh seals and grommet in place, and reinstall everything backwards. You need to replace the receiver/drier when any of these conditions happen: the system is dirty, the compressor or coils have been worked on recently, there's been a leak, or the system has stayed open for more than 24 hours. Disconnect the refrigerant, undo the clamps on the retaining screws, and lift the attached pipes and connections straight up from the top of the receiver/drier, throwing away the O-ring seals. After one hour without connection, block off any openings. You don't need to take off the fender liner on Z4 models to find your receiver drier. Loosen the clamp screws to take down the receiver/drier, follow the same steps to reattach it, making sure you recharge the refrigerant system. Before work on compressor and lines, prepare by pushing down the clutch lever, channeling any refrigerant exhaust into a container, and tieing down the vehicle. Take out the front splash shield to expose the compressor belt. Disconnect the fluid filling tube on the front windshield wiper, remove the compressor electrical wires, then unscrew and pull on the air conditioning lines while discarding the worn O-ring seals. To install the compressor, take off its mounting bolts and compressor, and return everything by working in reverse order when you're done. Make sure to put the proper level of refrigerant oil in, and put in new seals. To take out the pressure sensor above the receiver/drier, you have to run the system dry of refrigerant, unplug the wiring, loosen the sensor bolt, do the reverse process, and finish with a refrigerant refill. First, empty the refrigerant from the condenser, take off the air filter unit, and the radiator. You should first disconnect the refrigerant lines, then remove the screws holding the condenser by the base, and lift the whole thing away. Reinstallation proceeds backward, adding exactly the right amount of oil and putting fresh seals in their place. Take out the blower limit switch by unscrewing the bracket, separating the arm from the servo, removing the right-hand footwell air duct, and unscrewing the servo motor. Follow this sequence to remove the blower limit switch - disconnect wiring, remove screws, push back a clip, take out the switch, do reverse steps to reinstall.
Posted by BMWPartsDeal Specialist 
