Air Spring, Removing And Installing - BMW 5251 Service Manual

Rear Suspension
Air spring, removing and installing
CAUTION-
If vehicle is driven with airspring depressurized, the airspring
will be permanently damaged and must be replaced.
An air spring is made from a flexible rubber material which
forms an airtight cavity. It is pressurized by an air supply
pump activated by an electronic control unit to provide a vari-
. .
able spring rate depending on vehicle load
C A U T IO I G
Disable air supply pump by disconnecting electrical plug
before performing any repairs. Pump is located beneath a
cover under the spare tire in the floor of the cargo compart-
ment.
When removing and installing air connections, extreme
cleanliness must be followed. Small dirt particles can
cause leakage in the system.
Remove luggage compartment floor mat.
-
Working above air spring, loosen quick coupling screw con-
nection to allow air pressure to escape.
-
Once pressure has been reduced, retighten screw.
Tightening torque
Quick coupling screw
to
air pump
2
Nm
(18
in-lb)
-
Remove quick coupler. Plug openings to keep dirt out,
-
Remove air spring mounting clips.
-
Raise car and remove rear wheels.
Make sure the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place jaclc stands under
suspension parts.
-
Working underneath rear suspension, lift wheel bearing car-
rier to relieve rear spring tension. Then unbolt air spring
mounting bolt from seat on wheel bearing carrier. Remove air
spring.
NOTE-
Left and right air springs are different. The left air spring is
marked with a red identification marl. The right air spring is
marked with a blue identification mark.