Citytrac 4200
Citymaster 1200
Citycleaner
Service Documents
For internal use only
Status
March 2009
Page
58 of 108
raise/lower loading platform/container), the pressure regulator (Pos. 6) is opened via the control line on the pump side.
The oil then flows back through the open pressure regulator via connection T2 into the hydraulic oil tank.
If proportional valve Y5 (Pos. 9) is activated (energised), a quantity of oil adjustable between 5 and 20 l/min flows to the hydraulic
clutch (Pos. 147 / A3). This additional quantity is also used for those front attachment devices which require an increased quantity of
hydraulic oil (e.g. mulchmower). The pressure regulator (Pos. 6) is closed by Y5 via the control line and shuttle valves (Pos. 8). The
mechanical spring then takes effect against the oil flow and a maximum of 195 bar can be generated before the pressure regulator
(DBV) opens and enables the connection to the hydraulic oil tank.
In order to activate the raise front attachment support / pivot front attachment devices / raise platform/container functions, valve Y6
(Pos.10) is always triggered parallel. The hydraulic oil is fed to the valves (Y2 + Y3, Y7 + Y8, Y9 + Y10) via the connecting valve Y6. In
addition, Y6 also closes the pressure regulator via the control line and shuttle valve (Pos. 8). The mechanical spring then restricts the
flow of oil and a maximum of 195 bar is possible before the pressure regulator (DBV) opens and the connection to the hydraulic oil
tank is enabled (also refer to the description of Y5).
Note: In the event of a fault on the connecting valve Y6 (Pos.10) (electrical/mechanical), the downstream valves (Y2 + Y3
(Pos. 4.1), Y7 + Y8 (Pos. 4.2), Y 9 + Y10 Pos. 4.3)) are not supplied with oil, i.e. following a failure of the work hydraulics,
always check Y6 first.
When the proportional valve Y5 (Pos. 9) is energised, between 5 and 20 litres can be distributed to the consumers in a continuously
variable adjustment. When the maximum quantity of 20 l/min is extracted at the quick-release coupling (Pos. 147) at the front or rear of
the device, only approx. 8 l/min can be used for the following functions (raise/lower front attachment support, pivot front attachment
device, raise/lower loading platform/container).
If these functions only work when the potentiometer has been moved to its lower setting when the maximum quantity is extracted, the
feed quantity of the pump for these functions must be checked and readjusted using the A1 electronics as necessary.
A connection must be produced between the quick-release couplings for the attachment devices (Pos. 147/A3 and 151/B3).
