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LOCATION:    3.4 Adaptive Damping System (ADS 2) with electronic level control   >   34 Hydraulic Test Program - Internal Leakage Test, Front Axle Circuit

Hydraulic Test Program - Internal Leakage Test, Front Axle Circuit

Preparation for Test

Test only if rear axle vehicle level drops or does not raise.
Test with vehicle weight on all 4 wheels.
Test with vehicle at normal level.

1. Switch on level control lock-out switch (S77/1s1) (switch should illuminate).

2. Check oil level in oil reservoir (2), correct if necessary.
3. Disconnect overflow oil return line (LL/LR) for suspension strut (11) at connecter (arrow).
4. Connect coupling (038f) and bleeder screw (038n) to steel hydraulic line.
5. Disconnect return line (T) at oil reservoir (2), connect a suitable hose (061) and hold it in a measuring container.

  Test scope Test connection Test condition Nominal value Possible cause/Remedy
1.0   Internal leakage of leveling valve

Overflow quantity of suspension strut.
Measuring container. Overflow oil return hose (LL and LR ) in measuring container. Total overflow oil quantity:
2 cc in 4 hrs.

Replace ADS strut.

    Leveling valve Measuring container. Oil return line in measuring container.

Oil return flow should stop after 5 min.
Replace leveling valve.