General Information; General Information; Operator's Manual; Relieving Hydraulic System Pressure - Toro Groundsmaster 3500 30807 Service Manual

General Information

Operator's Manual

The Traction Unit and Cutting Unit Operator's Manuals
provide information regarding the operation, general
maintenance and maintenance intervals for your
Groundsmaster machine. Refer to these publications
for additional information when servicing the machine.

Relieving Hydraulic System Pressure

Before disconnecting or performing any work on the
Groundsmaster 3500 hydraulic system, all pressure in
the hydraulic system must be relieved. Park machine on
a level surface with the cutting units lowered and the
PTO switch off. Turn key switch to OFF and allow engine
to stop.
To relieve hydraulic pressure in traction circuit, move
traction lever to both forward and reverse directions. To
relieve hydraulic pressure in steering and lift circuits, ro-
tate steering wheel in both directions.

Traction Circuit Component Failure

The Groundsmaster 3500 traction circuit is a closed
loop system that includes the hydrostat and three (3)
wheel motors. If a component in the traction circuit
should fail, debris and contamination from the failed
component will circulate throughout the traction circuit.
This contamination can damage other components in
the circuit so it must be removed to prevent additional
component failure.
The recommended method of removing traction circuit
contamination would be to temporarily install the Toro
high flow hydraulic filter (see Special Tools in this chap-
ter) into the circuit. This filter should be used when con-
necting hydraulic test gauges in order to test traction
circuit components or after replacing a failed traction cir-
cuit component (e.g. traction (piston) pump or wheel
motor). The filter will ensure that contaminates are re-
moved from the closed loop and thus, do not cause addi-
tional component damage.
Groundsmaster 3500
To relieve cutting unit system pressure, turn key switch
to ON (engine not running). Move PTO switch to engage
which will energize the solenoid valve on hydraulic man-
ifold to relieve circuit pressure. Move PTO switch to dis-
engage, return key switch to OFF and remove key from
the ignition switch.
NOTE: Moving steering wheel with engine off may un-
seat implement relief valve. If steering or lift circuits ap-
pear weak or inoperative after machine is returned to
service, repeat relieving hydraulic system pressure pro-
cedure.
Once the Toro high flow hydraulic filter kit has been
placed in the circuit, raise and support the machine with
all wheels off the ground. Then, operate the traction cir-
cuit to allow fluid flow throughout the circuit. The filter will
remove contamination from the traction circuit during
operation. Because the Toro high flow filter is bi−direc-
tional, the traction circuit can be operated in both the for-
ward and reverse direction. The filter should be
removed from the machine after contamination has
been removed from the traction circuit. See Filtering
Closed−Loop Traction Circuit in the Service and Repairs
section of this chapter for additional information on us-
ing the Toro high flow hydraulic filter.
The alternative to using the Toro high flow hydraulic filter
kit after a traction circuit component failure would be to
disassemble, drain and thoroughly clean all compo-
nents, hydraulic tubes and hydraulic hoses in the trac-
tion circuit. If any debris remains in the traction circuit
and the machine is operated, the debris can cause addi-
tional circuit component failure.
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