Toro Groundsmaster 4500-D Service Manual page 116

Filtering Closed- Loop Traction Circuit
Filtering of a closed- loop hydraulic system after a major
component failure (e.g. traction (piston) pump, front
wheel motor or rear axle motor) is a requirement to pre-
vent debris from transmitting throughout the system. If
a closed- loop hydraulic system filtering tool is not used
to ensure system cleanliness, 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 hydraulic filter and hydraulic hose kit
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 and support machine so all wheels are off the
ground (see Jacking Instructions in Chapter 1 - Safety).
NOTE: If front wheel or rear axle motor was replaced,
install high flow filter to the inlet of new motor instead of
to the traction pump fitting. This will prevent system con-
tamination from entering and damaging the new motor.
3. Thoroughly clean junction of hydraulic hose and left
side fitting on bottom of piston (traction) pump (Fig. 62).
Disconnect hose from left side 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
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 low idle speed. Check for any
hydraulic leakage from filter and hose connections. Cor-
rect any leaks before proceeding.
CAUTION
All wheels will be off the ground and rotating dur-
ing this procedure. Make sure machine is well
supported so it will not move and accidentally
fall to prevent injuring anyone around machine.
IMPORTANT: While engaging the traction circuit,
monitor the high flow hydraulic filter indicator. If the
indicator should show red, either reduce traction
pedal setting or reduce engine speed to decrease
hydraulic flow through the filter.
Hydraulic System
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.
8. With engine running at high idle speed and traction
pedal moved to the forward direction, periodically apply
brakes to increase pressure in traction circuit. While
monitoring filter indicator, continue this process for an
additional five (5) minutes.
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.
9. 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.
10.Shut engine off and remove key from ignition switch.
11. Remove high flow hydraulic filter and hydraulic hose
kit from machine. Connect hydraulic hose to left side
piston (traction) pump fitting. Make sure to properly
tighten hose (see Hydraulic Hose and Tube Installation
in the General Information section of this chapter).
12.Lower machine to ground.
13.Check oil level in hydraulic reservoir and add correct
oil if necessary.
RIGHT
FRONT
1. Piston (traction) pump
Page 4 - 76
Rev. A
1
2
Figure 62
2. Left side fitting
Groundsmaster 4500- D/4700- D