If the vehicle is equipped with additional power cylinders, the line connections must face upward so
that the air in the cylinders and lines can escape. If necessary, slacken the power cylinders or
remove the cylinders.
Bleed the steering case by opening the threaded plug (7) located at the highest point (depending on
attitude) by 1/2 - 1 turn to allow any residual air to escape from the case at this point. As soon as
oil issues from the hole, retighten the threaded plug. Observe the oil level and top up if the level
drops. Then move steering wheel energetically several times from lock to lock. Add oil, if oil level in
Then repeat venting procedure. Open closing plug by 1/2 1 turn. As soon as oil flows out, close
plug again immediately and tighten to specified torque (refer to Technical Data). Add oil.
If the instructions above are followed, the oil level in the tank should not rise by more than approx. 1
to 2 cm, depending on the capacity of the steering system, when the engine is switched off. When
the vehicle is under way, the residual air still remaining in the steering system is negligible. This air
is absorbed by the oil while the vehicle is on the move and expelled.
Stop engine and lower steering axle or drive axle.
Checking the Oil Level
Check the oil level with the oil at operating temperature. Thoroughly clean the tank and its
immediate vicinity before removing the cap to prevent dirt entering the hydraulic oil.
Malfunctions may result if the oil level is too low.
Oil Level Checkup with Engine Stopped and Drive-Dependent Pump Not Driven:
To make sure that no air is sucked in when starting the engine, first check whether oil has been lost
on stopped engine. For this purpose, add oil into tank until the oil level is approx. 1 - 2 cm above the
upper mark of oil sight glass.
Checking Oil Level with Engine Running and Drive-dependent Pump Driven:
With the engine running and the drive-dependent pump driven (gear step engaged and the driving
axle for the drive-dependent pump jacked up), the oil level will slightly drop, since the oil requires a
pressure of 2 - 4 bar owing to the flow resistance while through steering gear.
Now add enough oil so that the oil level is constantly at upper mark. The engine can then be
stopped again. The oil level may rise max 1 to 2 cm. If this is exceeded, it is an indication that there
is air included in the oil.