Removal and installation the air conditioning battery/dehydrator (BMW 5 Series E28)

The battery/dehydrator is located behind the right headlight

Since working on the system is potentially dangerous, we strongly recommend that all work on the air conditioning system be performed by a BMW dealer or air conditioning specialist. At the very least, do not remove any components of the system (hoses, compressor, nipple connections, etc.) until the system is completely discharged by a qualified technician. Read the precautions at the beginning of Section Air Conditioner Maintenance and Precautions.

Removal

1. Discharge the air conditioning system (see warning above).

2. Disconnect the negative battery cable.

If your vehicle's radio is equipped with an anti-theft system, make sure you enter the correct code before disconnecting the battery.

If the instrument cluster displays the wrong language after connecting the battery, refer to Section Anti-theft audio system and instrument cluster language, which describes the procedure for installing the required language.

3. Remove the windshield washer reservoir.



4. Disconnect the electrical connector(s) from the battery/dehydrator - please note that not all models have both high and low pressure switches.

5. Disconnect the refrigerant lines from the accumulator/dehydrator.

6. Cap open fittings to prevent dirt and moisture from entering.

7. Remove the mounting screws and remove the battery/dehydrator.

Installation

If you are installing a new battery/dehydrator, you may need to add some refrigeration oil - if so, follow the manufacturer's instructions.

1. Remove the old seals from the refrigeration lines and install new ones. This should be done regardless of what accumulator/dehydrator is being installed.

2. If you are installing a new battery/dehydrator, remove the pressure switches from the old unit and install them on the new one before installing it. Not all models have both low and high pressure switches.

3. Lubricate the O-rings with refrigeration oil before installation.

4. Install in reverse order, but do not forget to lubricate the sealing rings with refrigeration oil before connecting the fittings.

5. Have the system drained, recharged and leak tested by the same qualified person who discharged it.