Installing Air Suspension Bellows
Information
To prevent damage to the air springs, be sure to follow all notices during handling and repair:
Rear air spring bellows
- The rear air spring bellows is supplied empty .
- Never lower a vehicle with empty air springs .
- Do not pull the air spring apart .
- Bend the air spring no more than 20° during removal and installation .
- Do not hold the air spring by its electric cable .
- Carefully transport the air spring -1- only at the top -2- and bottom of the mounting -3- .
Information
The terms "Ignition on" and "Starting engine" are re-defined for fully electric vehicles (battery electric vehicles - BEV).
Establishing operational readiness/Ignition on:
Prerequisites for establishing operational readiness: High-voltage battery is sufficiently charged, remove vehicle charging cable from the vehicle charge port, put driver's key in the emergency start tray.
Establishing operational readiness automatically: Get into the vehicle and close the driver's door. The driver's key is recognized inside the vehicle. Operational readiness is established.
Establishing operational readiness manually: Press Start/Stop switch. The driver's key is recognized inside the vehicle. Operational readiness is established.
Establishing operational readiness/Starting engine:
Establish operational readiness and engage transmission range. The vehicle is now ready to drive and can be moved.
Ending operational readiness/Switching off ignition
Ending operational readiness automatically: Get out of the vehicle with the driver's key and close the driver door. The driver's key is no longer detected outside the vehicle. Operational readiness ends.
Ending operational readiness manually: Press Start/Stop switch until the instrument cluster is switched off.
Ending driving readiness/Stopping engine
Vehicle is stationary: Press the P button on the instrument cluster. The vehicle is parked.
- Check whether the clip -1-
in the top mounting -3-
of the air suspension bellows -2-
can still be used (no spare part). If not, remove clip -1-
.
Clip on air suspension bellows
Information
Check the following before installing the air line:
- Check that the cutting ring -1- and Voss threaded joint -2- are on the air line -3- (not relevant if the air spring bellows was replaced and the Voss threaded joint that is pre-fitted on the air spring bellows is used).
- Check that the air line is fitted correctly.
Checking air line
Only one marking -1- on the air line should be visible.
Pull the air line briefly against the insertion direction. If it cannot be pulled out, the air line is fitted correctly.
Checking that air line is fitted correctly
Information
- The air spring bellows must only be filled if it has first been positioned correctly in the trailing arm .
- The cable for the air spring bellows must be in the groove on the lower trailing arm .
- To do this, use a jack to lift the lower trailing arm until the upper support of the air spring bellows is touching the upper mounting .
- Align air suspension bellows in the lower trailing arm.
Aligning air suspension bellows in lower trailing arm
- 2.1 Carefully guide air suspension bellows between the upper rear control arm and anti-roll bar.
- 2.2 Route electric line -1- on the air suspension bellows and insert air suspension bellows into the lower control arm in such a way that the electric line -1- is in the cut-out -2- .
- Fit air line -1-
to air suspension bellows -2-
and fit and tighten Voss threaded joint -3-
on the air line -1-
.
> Tightening torque 3 Nm (2 ftlb.)
Air line for air suspension bellows
- Connect and lock electric plug connections -1 and 2-
on air spring bellows -3-
.
Electric plug connections on air suspension bellows
- Fasten rear upper control arm -1-
on the wheel bearing housing -2-
.
- 5.1 Fit rear upper control arm -1- into the wheel bearing housing -2- .
- 5.2 Insert new screw -4- and screw on new nut -3- , but do not tighten yet.
Rear upper control arm on wheel bearing housing
Information
Threaded joints must only be tightened in zero position to prevent warping in the bearings.
- Pre-fill air suspension bellows using the PIWIS Tester
.
Proceed as follows for one air suspension bellows:
- 6.1 Connect the PIWIS Tester to the vehicle and switch it on.
- 6.2 Establish operational readiness/switch on ignition.
- 6.3 Start diagnostics.
- 6.4 Select "Chassis control PASM" control unit.
- 6.5 Select the "Maintenance/repairs" tab.
- 6.6 Select the menu item "Replacement work on the air spring system" and press F12 to continue.
- 6.7 Select the "Replacement of an air spring" function and press F12 to continue.
- 6.8 Select the "Filling an air spring" function and press F12 to continue.
- 6.9 Select the relevant air spring and press F8 to start the pre-filling process.
Pre-filling takes 5 seconds and stops automatically. Guide the air suspension bellows into the upper mounting as it expands.
If the clip is still usable, clip air suspension bellows onto the body at the top (if possible) .
- 6.10 See further information.
WARNING: Wheel bearing housing raised incorrectly- Risk of crushing
- Risk of damage to components
→ Wear personal protective gear.
→ Do not raise the wheel suspension higher than the normal vehicle position (vehicle resting on wheels).
- Raise wheel suspension to zero position using > VAS 6931 - engine and gearbox jack
. > Zero position (shown on rear axle as an example)
Zero position (shown on rear axle as an example)
- 7.1 Zero position corresponds to the vehicle height during alignment .
- Tighten threaded connection for rear upper control arm -1-
.
- 8.1 Tighten collar nut -3- and counter at screw -4- .
> Tightening torque 70 Nm (52 ftlb.)
> Torque angle + 90 °
Rear upper control arm on wheel bearing housing
- Continue filling the air suspension bellows using the PIWIS Tester .