Accumulator: Service and Repair

37 22 540 - Replacing air supply unit





Warning!
Risk of injury!
Drain the air spring system before carrying out any work on the air supply unit, air pipes and air springs! Danger of injury if this instruction is not complied with!
Risk of damage!
The vehicle must not stand on its wheels when the air springs are depressurized! Otherwise the air spring struts will be damaged and later destroyed during driving!
Extreme cleanliness must be ensured in the connection area of the pipes during removal and installation. Even the smallest of dirt particles can cause leakage in the air spring system.





Important!
To prevent premature failure of the air supply unit, it is essential to replace the air supply unit relay Removing and Installing/Replacing Air Supply Unit Relay as well!

Note:
Read and comply with notes on air spring system Notes on Air Spring System.





Necessary preliminary tasks:
- Remove battery compartment cover from floor plate.
- Deactivate and drain air spring system Draining/Filling Air Spring System





Important!
Do not kink, twist or crush lines.





Disconnect plug connection.
Release banjo bolts.
Tightening torque 37 12 3AZ Control and Suspension Elements, Rear.
Lay pipes to one side and seal off with adhesive tape.

Installation Note:
Check banjo bolts for dirt, clean if necessary. Then carefully screw in banjo bolts by hand to avoid damaging the plastic threads and with it the air supply unit.





Important!
To prevent premature failure of the air supply unit due to the ingress of dirt particles and moisture, it is essential to replace the feed line (becomes porous) as well!

Partially remove rear right wheel arch cover Service and Repair.

Disconnect feed line (1) of air supply unit from vent line (2).
Seal off feed line (1) of air supply unit and vent line (2) with adhesive tape.





Disconnect plug connections (2).
Unscrew nuts (1).
Tightening torque 37 22 1AZ Pump Unit with Reservoir.
Remove air supply unit (3).





After installation:
- Activate and fill air suspension system Draining/Filling Air Spring System