Sitting
Vehicle: All Technical Service Bulletins
Suspension - Vehicle Drops At Rear Axle After Sitting
Vehicle drops at rear axle, vehicles with
electronic rear axle level control or AIRmatic
Topic number L132.22-P-048597
Version 2
Design group 32.22 Air suspension
Date 01-25-2013
Validity Model 212.0## with air suspension (SA code 489) up to
VIN 212.0## ## 620947
Model 212.2## (wagon) up to VIN 212.2## ## 620947 Model 218 with air suspension (SA code 489) up to VIN 218 ### ## 055091
Reason for change Validity updated
Complaint:
The vehicle drops at the rear axle after standing for a long time.
Cause:
Damaged sealing rings in the air suspension element on the rear axle can lead to a microscopic leak and thus to a gradual loss of air.
Attachments
Remedy:
Check for water in the system:
1. Unscrew AIRmatic pressure line between compressor and valve unit.
If water runs out (Figure 1) or if water droplets are visible at the pressure line connection of the compressor or valve unit (Figure 2), the compressor, the valve unit and the air filter of the intake hose must be replaced.
If no water is visible, actuate compressor. If water runs out of the connection on the compressor, replace the compressor, the valve unit and the air filter of the intake hose.
If the components are replaced due to water in the system, this is to be encoded in the warranty and goodwill case as consequential damage for the air spring bellows.
(Observe WIS instructions.)
2. Unscrew air lines from valve block to air springs on the side of the air suspension strut and blow out with compressed air.
3. Replace both air springs on the rear axle.
Note :
Since the end of December 2011 modified air spring bellows are available with which the problem can be permanently eliminated - see part numbers below. Even if one or both air spring bellows have been replaced in the past and the vehicle has started to drop at the rear axle again, the cause of the problem is still the air spring bellows. We are unaware of any other damage mechanism/focus. In this case both air spring bellows must be replaced again.
Possible check for confirming the complaint 'vehicle drops':
1. Park up the vehicle and after approx. 2 hours, when the vehicle has cooled down, measure the vehicle level at the rear axle on both sides from the
wheel center to the fender.
2. Leave the vehicle standing overnight in the same place and next day check the vehicle level at both wheels. If the vehicle level has dropped by
more than 20 mm, both air suspension elements must be replaced.
Symptoms
Parts
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