Functions and parameters
Hydraulic system 6000
Publication No. Date Valid from serial number T-code
261828-040 2008-08-21 6051502 815, 816
© BT Repair Manual RRE140/160/180/200/250 4 – 63
Simultaneous operation of mast lift and reach
movement
Under normal circumstances the flow for mast lift and the reach move-
ment are regulated by pump speed.
To allow simultaneous operation of these functions, the flow must
instead be limited using the proportional valves Q2/Q3 and Q6/Q7.
This reduces the maximum speed of mast lift and reach movement
when simultaneously operated.
4.10.8 Extra functions
Extra functions are activated by valve Q8/Q9, non-replaceable, in the
main valve block.
If Q8 is activated, pump pressure P is connected to connection A1, and
connection B1 is connected to T (tank return).
If Q9 is activated, pump pressure P is connected to connection B1, and
connection A1 is connected to T (tank return). Pump speed regulates
the speed, and current limitation of the electric motor determines the
pressure level for the extra function.
4.10.9 Cabin tilt (RRE Ergo)
Cabin tilt is controlled by a proportional slide valve, Q11/Q21, non-
replaceable.
To lift the cabin (tilt it up), the pump is started and Q11 is activated, and
to lower the cabin, Q21 is activated.
Hydraulic priority system
The priority system means cabin tilt takes priority over mast lift.
If both functions are activated, cabin tilt will not be affected, whereas
the flow for mast lift is limited.
The normal position of the priority system valve directs the pump flow to
the proportional valve for cabin tilt Q11/Q21.
If Q11/Q21 is open, the flow travels to the cabin tilt cylinder, and if Q11/
Q21 is not open, the pressure increases and causes the priority system
valve to move, so that the flow travels to mast lift Q2/Q3.
If Q2/Q3 is open, the flow travels to the main lift cylinders or the free lift
cylinder, respectively; if Q2/Q3 is not open, the pressure increases and
affects the pressure reducing valve, DV1, which opens the path to the
tank.
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