Bleeding, Draining and Refilling of Hydraulic System
Hydraulic system - Draining and refillingModel 140
Draining pressure oil system
- Remove linkage (7) at lever on level control unit.
- Attach oil drain hose (061) at oil drain plug (3p) on level control unit (3).
- Slowly open oil drain plug (3p) whilst catching the oil in a clean container. Then retighten oil drain plug (3p), 14 Nm.
Filling pressure oil system
- Fill hydraulic oil into the oil reservoir (2) using funnel 126 589 12 63 00, until the oil level is between "min" and "max" markings on the oil dipstick.
- Press lever on level control unit into position "Fill". Install linkage (7), replace self-locking bolts, 10 Nm.
- Start engine and allow to run for approx. 30 seconds in the middle speed range, then switch off engine (note information in No.8)
- Check oil level in oil reservoir, the oil level must be between the "min" and "max" markings when the engine is not running.
Special Tool:
Scope of work
Draining pressure oil system
1 If the linkage is fitted. Remove linkage (7) at lever on level control unit.
Notes
Designations on level control unit
A = Model 140 with level control on rear axle
B = Model 140 with level control on rear axle and ADS.
Modified fluid drain plug on level controller
A new fluid drain plug (3m) was installed at connection '52 on the level controller. The earlier connection fitting (3m) was deleted at the same time. Tightening torque for fluid drain plug: 14 Nm.
A = Version installed up to 9/92
B = Version from 10/92 onward
2 Attach oil drain hose (061) to oil drain plug (3p) on the level control unit (3).
3 Slowly open oil drain plug (3p) whilst collecting the oil in a clean container. Then retighten oil drain plug, 14 Nm.
Filling pressure oil system
4 Use funnel with strainer (060) to fill oil reservoir (2) with oil collected.
Note: Only re-use clean oil.
5 Check oil level in oil reservoir, top up if necessary. To fill the system when spring struts are empty the oil level should be approximately at the maximum marking (a).
6 Move lever on level control unit into position Fill" and allow engine to run at medium speed for approx. 30 seconds
F = Fill
L = Drain
7 Install linkage rod (7) using new self-locking hexagon bolts, 10 Nm.
8 Check oil level in oil reservoir (2) when engine is not running and correct if necessary. When the system is operational the oil level should be between markings "max." and "mm" at curb weight. It the vehicle is fully laden the oil level is thus below the "m in" marking (no longer visible on dipstick).
Note: Only use approved hydraulic fluids.
Caution! If during repair work the oil reservoir has been emptied or the tandem pump replaced or high pressure extending hose unscrewed, the pump must be bled.
For this step, when the engine is running press the lever of the level control unit into position "Empty" or "Neutral" to ensure the oil returns to the oil reservoir (this is already the case on a raised vehicle). If no oil is supplied to the oil reservoir on ASD vehicles, also hold the high pressure extending hose disconnected at the steel line in a container until no bubbles appear in the escaping oil. Then repeat the work steps Nos. 4-8.