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LOCATION:    3.4 Adaptive Damping System (ADS 2) with electronic level control   >   33 Hydraulic Test Program - Leveling Valve Pressure Test

Hydraulic Test Program - Leveling Valve Pressure Test

Preparation for Test

1. Depressurize rear axle hydraulic system by slowly opening bleed screw (57a).
2. Connect test gauge (038) with hose (038e) to distribution fitting (57) in place of bleed screw (57a).
3. Check oil level in oil reservoir, correct if necessary.
4. Connect HHT (refer to section 0).

Monitor oil level during testing, air must not be allowed to enter the system through the hydraulic pump.

  Test scope Test connection Test condition Nominal value Possible cause/Remedy
1.0   Leveling valve
Opening pressure
Relief valve

Overflow valve
250 bar at rear axle distribution fitting Engine: at Idle
HHT activation: raise

HHT activation: lower
(5 min)
180 - 190 bar

33-36 bar after 5 min.
Delivery pressure > 190 bar Replace leveling valve.
Delivery pressure < 180 bar
Hydraulic pump test 32.

Replace leveling valve.