Diagnostic Manual, Chassis and Drivetrain,
Volume 1
Hydraulic Test Program - Leveling Valve Pressure Test
Preparation for Test
1. Check oil level in oil reservoir, correct if necessary.
2. Model 129
Disconnect connecting rod at front and rear leveling valve levers
(set levers to neutral position) (Figure 1).
Model 140
Disconnect connecting rod at rear leveling valve levers
(set lever to neutral position) (Figure 2).
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.
Model 129
Front axle: Connection "6p"
Model 140
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, check font axle struts for fluid leaks 36 1.0.
Note:
If front axle struts are not leaking, replace leveling valve.
|
 |
| 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 rear axle leveling valve |
Engine: at Idle
Set leveling valve lever to "F" (fill). |
133 - 153 bar |
> 153 bar
Replace leveling valve.
< 133 bar
Check hydraulic oil pump 32
|
| 2.0 |
Overflow valve function |
250
Connect test gauge to 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.
|
|
Printable version
