2001 BMW 525i air suspension

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330-30
I Rear Suspension
Remove right and left lower strut mount bolts (arrow).
Remove rear suspension subframe by removing 4 mounting
bolts
(arrows).
Carefully lower rear suspension subframe away from body to
remove.
To install, jack
subframe into position. Install and t~ghten sub-
frame mounting bolts. Note that on each bolt, rubber-coat-
ed detent plate
(arrow) must be installed at rear in driving
direction.
Models
w~th coil springs: Fit springs correctly in lower
spring seats.
Models with air suspension: Fit eccentric lug at bottom of
air
sprlng in recess of wheel carrier spring seat.
Tightening torques
-
Air spring to wheel bearing carrier 20 Nm (1 5 ft-lb)
Rear subframe to body (M12) 163 Nm (120 ft-lb)
-

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Rear Suspension
- Remainder of installation is reverse of removal, noting the fol-
lowing.
Tighten suspension arm and shock absorber fasteners to
final torque only afler vehicle has been lowered and sus-
pension has settled.
Tightening torques
ABS pulse sensor to wheel bearing carrier 8
Nrn (6 ft-lb)
Air line connection 2 Nrn (18 in-lb)
Brake rotor to hub 16
Nrn (12 ft-lb)
Driveshaft
CV joint to final drive flange
- MI0 (Torx bolts) 70
Nrn (51 ft-lb)
- MB (compression nut) 32 Nrn (24 ft-lb)
Rear
brake pad carrier (caliper) to wheel 65
Nrn (48 ft-lb)
bearing carrier
Road wheel to hub
120ilO Nrn
(89 i-7 ft-lb)
Rear subframe mounting bushings,
removing and installing
- Remove rear subframe mounting bolts as described earlier.
Lower
subframe approximately 40 - 45 mm (1 -2 in).
4 Install BMW special tools 33 4 140,33 4 151,33 4 154,33 4
155,33 4 156 as shown.
Use hot air gun with a maximum output temperature of
600°C (1100" F) to heat bushing area of subframe for no
more than
2 minutes. Remove rubber mount from sub-
frame.
CAUTION-
Aluminum suspension parts may be severely damaged
witli intense heat
* Heating for 2 minutes with the recommended heat
source is intended to
keep the temperature of the alu-
minum
parts below the safety threshold of 80°C
(1 76°F). .

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330-35
Rear Suspension
- Remainder of installation is reverse of removal, noting the fol-
lowing.
Always use new self-loclting nuts.
Make sure all threaded bolts, nuts and mating suriaces are
clean.
Make sure long lower strut bushing fits in hole in wheel
bearing carrier.
Tighten fasteners to final torque only after vehicle has
been lowered and suspension has settled.
Stake axle collar nut after tightening.
Tightening torques
ABS pulse sensor to wheel bearing carrier
8 Nm (6 ft-lb)
Brake rotor to hub 16 Nm (12 ft-lb)
Rear brake pad carrier (caliper) to wheel 65
Nm (48
ft-lb)
bearing carrier
Rear axle shaft to hub
(M27) 300 Nm (221 ft-lb)
Rear strut to wheel bearing carrier 127
Nrn (94 ft-lb)
Road wheel to hub
120+10 Nm
(89
i7 ft-lb)
Swing arm to wheel bearing carrier 256
Nrn (189 ft-lb)
Upper front control arm (traction strut) to 65 Nrn
(48
ft-lb)
wheel carrier
Upper rear control arm to wheel carrier 142
Nrn (105
ft-lb)
Rear wheel bearing carrier, removing and
installing (Sport Wagon models)
- Raise rear end of car and remove wheel.
WARNING-
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 jack stands under
suspension parts.
Models
with air springs: Disable air supply pump by discon-
necting electricalplug
beforepedormingany repairs. Pump is
located beneath a cover under the spare tire in the floor of the
cargo compartment.
-- 4 Models with air springs: Loosen compressed air pipes (ar-
rows) at air distribution assembly to release system pres-

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330-36
l~ear Suspension
- 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.
- Models with rear coil springs: Remove cargo compartment
floor carpet.
Working at top of coil spring, press center cap down or pry
upward to remove. If pushed down, remove from inside
coii
spring from under car.
< Working from underneath, position BMW special tool 33 2
301
between 2nd and 3rd spring coii from bottom.
Make sure tooi recess faces upward.
Working in cargo compartment, guide
BMW special tooi 33
2 304
from above and thread into special tool 33 2 301.
4 Working in cargo compartment, attach BMW special tools 33
2
302,33 2 303 and 33 2 305 to special tool 33 2 304.
Use special tool 33 2 306 to compress spring.
Tighten until lower spring coil
lifts off sprrng seat on wheel
bearing carrier.

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330-39
I Rear suspension1
- Remainder of installation is reverse of removal, noting the fol-
lowing.
Models with coil springs: Fit spring correctly in lower spring
seat.
* Models with air suspension: Fit eccentric lug at bottom of
air spring in recess of wheel carrier spring seat.
Always use new self-locking nuts.
- Make sure all threaded bolts, nuts and mating surfaces are
clean.
a Tighten fasteners to final torque only after vehicle has
been lowered and suspension has settled.
Stake axle collar nut afler tightening.
Tightening torques
ABS pulse sensor to wheel bearing 8 Nm (6
ft-lb)
carrier
Air spring to wheel bearing carrier 20 Nm (15 ft-lb)
Brake rotor to hub 16 Nm (12
it-lb)
Rear axle shaft to hub (M27) 300 Nm (221 ft-lb)
Rear brake pad carrier (caliper) to wheel 65 Nm (48 ft-lb)
bearing carrier
Road wheel to hub
120ilONm
(89 k7 ft-lb)
Swing arm to wheel bearing carrier 256 Nm (189 it-lb)
Upperfrontcontrol arm (traction strut) to 65 Nm (48 ft-lb)
wheel carrier
Upper rear control arm to wheel carrier 142 Nm (105 ft-lb)
Rear wheel bearing, replacing
< The rear wheel bearing is integrated with its mounting flange.
1. Torx bolt
2. Wheel bearing and mounting flange
3. Wheel hub
4. Collar nut
- Raise rear end of car and remove wheel.
WARNING -
Make sure the car is firmly supported on jaclc stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place jack stands under
suspension parts.

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---
Rear Suspension
ELECTRONIC HEIGHT CONTROL
(EHC) COMPONENT REPLACEMENT
Sport Premium rear suspension is an option on Sport Wagon
models and standard on
1999 and later V-8 Sport Wagons.
This suspension incorporates electronic height control
(EHC)
using air springs.
With vehicle lifted off the ground,
if the rear air springs can be
compressed by hand, either the spring is defective or the sys-
tem is depressurized.
Locate
EHC faults using BMW scan tools DIS or MoDiC. EHC
description and some troubleshooting is covered in 300 Sus-
pension, Steering and Brakes-General.
Air spring replacement is covered earlier in this chapter. See
Air spring, removing and installing.
CAUTION-
Maintain high levels of cleanliness around air line connec-
tions when disassembling and assembling air suspension
components. Even
small dirt particles can cause leakage in
the pressurized system.
Electronic height control
(EHC) components
1. Air spring
2. 1 liter air reservoir
3. EHC control module
4. Air supply distributor
5. Airsupply pump
(under spare tire)
6. Air spring mounting bolt
(at wheel bearing carrier)
7. Rear ride height sensors
(Hall effect)
8. Air supply pump relay

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-- I
I: ... . -. Rear Suspension! -- .- -
Air compressor pump relay, removing and
installing
- Working in cargo compartment, remove spare wheel.
4 Remove air supply pump fasteners (arrows). Turn pump
over.
- Turn relay plug 45" and remove relay.
EHC control module, removing and
installing
The EHC control module is mounted on the right side of the
spare tire
well in the cargo compartment.
- Remove spare tire.
4 Remove electrical components cover (A).
- Release control module wiring harness plug loclting clip (B)
and remove module.
- Installation is reverse of removal.
- After assembly, reset ride height using BMW diagnostic scan
tool DIS.
Air supply unit, removing and installing
CAUTION-
Maintain high levels of cleanliness around air line connec-
tions when disassembling and assembling air suspension
components. Even small dirt particles can cause
leakage in
the pressurized system.
When the airsupply unit is removed for any reason, reset ride
height using BMW scan tools DIS or
MoDiC.
- Remove spare tire.
i~B,!n,,ayPubi.l,c~u.c~"~-A~~ R

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Rear Suspension
4 Remove air line fittings (A) from bottom of air distribution con-
nectors.
Cut off wire ties.
WARNING-
Vehicle will lower when the air pipes are opened.
4 Rotate air line distribution connector (A) 45" in direction of
arrow to remove.
Rotate electrical connector
(B) 45" in direction of arrow to
remove.
Compress wiring connector locking clips
(arrows) and dis-
connect wiring harness.
< Remove air supply unit mounting fasteners (arrows) and re-
move unit.
- Installation is reverse of removal.
When installing air lines always match line colors.
a After assembly, reset ride height using BMW diagnostic
scan tool DIS.