STAR TekInfo

STI Home

Body And Accessories

Chassis & Drivetrain

Diagnostic Manual, Chassis and Drivetrain,
Volume 1

Printable version

LOCATION:

3.1 Adaptive Damping System (ADS) > 34 Hydraulic Test Program - Leveling Valve Pressure Test

Hydraulic Test Program - Leveling Valve Pressure Test

**Preparation for Test**
1. Check oil level in oil reservoir, correct if necessary. 2. Unscrew connecting rod at front and rear leveling valve levers (set levers to neutral position). 3. Depressurize hydraulic system by slowly opening bleeder screw (3p or 6p). Connect drain hose and place into container. 4. Connect test gauge to leveling valve bleeder screw. Front axle: Connection "6p" Rear axle: Connection "3p" or leveling valve connection S2.

Test step Test scope Test connection Test condition Nominal value Possible cause/Remedy

1.0 Opening pressure of relief valve

WARNING!
High Pressure 250
Connect test gauge to front or rear axle leveling valve Engine: at Idle
Set leveling valve lever to "F" (fill). 133 - 153 bar > 153 bar
Replace leveling valve.

< 133 bar
Set leveling valve on other axle to "F" (fill) and read pressure again.

If new pressure reading is:

> 133 bar
Check pressure supply screw (50a) for proper seating,
Replace valve assembly.

< 133 bar
33 1.0

Note:
If delivery capacity > 0.2l/min., replace leveling valve.

2.0 Overflow valve function 250
Connect test gauge to front or rear axle leveling valve Engine: at Idle
Set leveling valve lever to "F" (fill) until gauge indicates approximately 80 bar.

Set leveling valve lever to "L" (empty)

30 - 36 bar

Rear axle:
Replace leveling valve.

Front axle:
> 36 bar, replace leveling valve.
< 30 bar, 36 1.0.

Note:
If front axle struts are not leaking, replace leveling valve.