Service Manual

Multi Pro 5800Hydraulic System Page 5 − 14
Spray Pump Drive Circuit
A two (2) section gear pump is coupled to the piston
(traction) pump. The front gear pump section (closest to
the piston pump) supplies hydraulic flow to the spray
pump drive circuit. The rear gear pump section supplies
hydraulic flow to both the steering and spray boom lift/
lower circuits. The gear pump takes its suction from the
hydraulic reservoir.
Hydraulic flow control for the spray pump drive motor is
completed by the spray pump control manifold. The
spray pump control manifold is mounted directly to the
hydraulic motor that drives the spray pump. The pump
control manifold includes a solenoid controlled propor-
tional valve (PV) that allows adjustment of the hydraulic
flow to the spray pump motor. A pressure compensator
valve (LC) located in the pump control manifold main-
tains a pressure differential of 80 PSI (5.5 bar) across
the proportional valve (PV). Spray pump circuit pressure
is limited to 2000 PSI (138 bar) by a relief valve located
in the spray pump control manifold.
Spray pump drive circuit hydraulic flow can be moni-
tored at the outlet of the front gear pump section. Circuit
pressure can be measured at a diagnostic fitting in port
G on the spray pump control manifold.
Machines with manually operated spray systems use
the spray pump On/Off and application rate switches as
inputs to adjust the electrical current to the control man-
ifold solenoid (adjustable application rate).
Machines with ExcelaRate or GeoLink spray systems
use the spray pump enable switch, the application rate
switch, the flow meter and the speed sensor as inputs
to adjust electrical current to the control manifold sole-
noid (variable application rate).
Spray Pump Enable Switch ON (Fig. 10)
With the engine running and the spray pump enable
switch in the ON position, the proportional valve (PV) in
the spray pump control manifold is energized. Based on
available current (mA) supplied by the TEC, the spool in
the proportional valve directs some gear pump flow out
the M1 port of the manifold to the spray pump hydraulic
motor. This hydraulic flow causes the motor to rotate the
spray system pump for spray system operation. The
manifold pressure compensator valve (LC) maintains a
pressure differential of 80 PSI (5.5 bar) across the pro-
portional valve (PV). Any excess flow above what the
proportional control valve is electrically adjusted for, is
by−passed to the reservoir through the compensator
valve. Hydraulic flow returns out the manifold T port, to
the oil cooler and then to the hydraulic oil reservoir.
Figure 11
Spray Pump Switch in OFF Position
(Spray Pump Motor NOT Rotating)
SPRAYER PUMP DRIVE MOTOR
6.0 CID
PV
CV
OR
.040”
80 PSI
LC
2000 PSI
G
PT
PUMP CONTROL
MANIFOLD
Spray Pump Enable Switch OFF (Fig. 11)
With the engine running and the spray pump switch in
the OFF position, the solenoid valve in the spray pump
control manifold is not energized. All gear pump flow to
the manifold is routed through the pressure compensa-
tor valve (LC) in the manifold, directed out the T port of
the manifold, to the oil cooler and returns to the hydraulic
oil reservoir. The spray pump hydraulic motor receives
no hydraulic flow so the spray system pump is not ro-
tated and no spray system flow is available.
The spray pump application rate (increase/decrease)
switch allows the operator to adjust electrical current to
the proportional valve (PV) solenoid via the TEC. Higher
current (rate increase) to the proportional valve solenoid
increases hydraulic flow to the spray pump motor and
results in a higher spray pump speed with more spray
system output/pressure. Lower current (rate decrease)
to the proportional valve solenoid decreases hydraulic
flow to the spray pump motor and results in a lower spray
pump speed with less spray system output/pressure.