Filtering Closed--Loop Traction Circuit; General Information 5 - Toro 04384 Service Manual

Filtering Closed- -Loop Traction Circuit
Filtering of a closed--loop hydraulic system after a major
component failure (e.g. piston (traction) pump or wheel
motor) is a requirement to prevent debris from transmit-
ting throughout the system. If a closed--loop hydraulic
system filtering tool is not used to ensure system cleanli-
ness, repeat failures, as well as subsequent damage to
other hydraulic components in the affected system, will
occur. To effectively remove contamination from
closed--loop traction circuit, use of the Toro high flow hy-
draulic filter and hydraulic hose kits are recommended
(see Special Tools in this chapter).
1. Park machine on a level surface with engine stopped
and key removed from ignition switch.
2. Raise machine so all driven wheels are off the
ground. Support raised machine with appropriate jack-
stands.
NOTE: If wheel motor was replaced, install high flow fil-
ter to the inlet of new motor instead of to piston (traction)
pump fitting. This will prevent system contamination
from entering and damaging the new motor.
3. Thoroughly clean junction of hydraulic hose and
lower fitting on side of piston pump (Fig. 32). Disconnect
hose from lower pump fitting.
4. Connect Toro high flow hydraulic filter in series be-
tween piston pump fitting and disconnected hose. Use
hydraulic hose kit (see Special Tools in this chapter) to
connect filter to machine. Make sure that fitting and hose
connections are properly tightened.
IMPORTANT: Use only hydraulic fluids specified in
Traction Unit Operator's Manual. Other fluids could
cause system damage.
5. After installing high flow filter to machine, check and
fill hydraulic reservoir with new hydraulic oil as required.
6. Start engine and run at idle speed. Check for any hy-
draulic leakage from filter and hose connections. Cor-
rect any leaks before proceeding.
CAUTION
All driven wheels will be off the ground and rotat-
ing during this operation. Make sure machine is
well supported so it will not move and accidental-
ly fall.
Hydraulic System
IMPORTANT: While engaging the traction circuit,
monitor the indicator on the high flow hydraulic fil-
ter. If the indicator should show red, either reduce
pressure on the traction pedal or reduce engine
speed to decrease hydraulic flow through the filter.
7. With engine running at low idle speed, slowly move
the traction pedal to the forward direction to allow flow
through the traction circuit and high flow filter. Keep trac-
tion circuit engaged for five (5) minutes while gradually
increasing both forward pressure on traction pedal and
engine speed. Monitor filter indicator to make sure that
green color is showing during operation.
IMPORTANT: If using a filter that is not the bi- -direc-
tional Toro high flow filter, do not press the traction
pedal in the reverse direction. If flow is reversed
when using a filter that is not bi- -directional, debris
from the filter will re- -enter the traction circuit.
8. With engine running at high idle speed, alternately
move traction pedal from forward to reverse. While mon-
itoring filter indicator, continue this process for an addi-
tional five (5) minutes.
9. Shut engine off and remove key from ignition switch.
10.Remove high flow hydraulic filter and hydraulic hose
kit from machine. Connect hydraulic hose to lower pis-
ton (traction) pump fitting. Make sure to properly tighten
hose (see Hydraulic Hose and Tube Installation in the
General Information section of this chapter).
11. Lower machine to ground.
12.Check oil level in hydraulic reservoir and add correct
oil if necessary.
1. Piston pump
Page 4 - - 54
1
Figure 32
2. Lower hydraulic hose
Greensmaster 3250--D
2