The receiver/drier acts as a filter in the A/C system. It
must be changed when the A/C system is opened for repair.
There is two types of driers, one with 3 switches (Bmw E34
before 2/1989) and one with one switch (Bmw E34 after 2/1989)
It is located in the front right corner of the engine compartment
below the headlight.
Procedure
System need to be discharged.
New O'rings.
Rachet, extensions.
New pressure switch if you have an E34 built before 2/1989
1. Discharge the system if not already done (Don't release
it on the atmosphere PLEASE).. Remove the plastic cover at
the back of the headlight. Remove the air filter box.
2. Disconnect the connectors from the windshield washer and
move the windshield washer to the air filter box location.
(You can also remove the washer pump and leave the air box
alone).
3. Disconnect the connectors from the drier pressure switch(es).
Remove the 3 screws holding the drier. Remove the drier and
remove the pressure switch if E34 built after 2/1989.
Up to 1/1989 E34 ONLY
4. This is a picture of an old drier. You can see the separate
high, low and intermediate pressure switches. The new ones
use one switch.
Up to 1/1989 E34 ONLY
5. Cut off the two spades, splice then wire ends and solder
them together. Use shrink wrap or electrical tape to isolate
the wire.
6. Install the new pressure switch (or used one
in case of an after 2/1989 E34) in the drier and install the
drier back to its location. Connect the two A/C lines and use
new O'rings. Tighten the 3 screws and connect the two connectors
(black to black and white to white). Installation is reverse
of removal