Toro Groundsmaster 4500-D Service Manual page 89

Procedure for Traction Assist (RV2) Pressure Test
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine for approximately 10
minutes. Make sure the hydraulic tank is full.
2. Park machine on a level surface with the cutting units
lowered and off. Make sure engine is off and the parking
brake is engaged.
CAUTION
Prevent personal injury and/or damage to equip-
ment. Read all WARNINGS, CAUTIONS, and Pre-
cautions for Hydraulic Testing at the beginning
of this section.
3. Connect a 1000 PSI gauge to counterbalance test
port on power down and traction assist manifold under
operator's seat (Fig. 51). Also, connect a 5000 PSI
gauge to forward traction port on traction circuit hydrau-
lic tube (Fig. 52).
4. Start the engine and put throttle at full engine speed
(2800 + 50 RPM) with no load on the system. Do not en-
gage the cutting units.
5. Sit on seat, apply brakes fully, and slowly depress the
traction pedal in the forward direction. While pushing
traction pedal monitor both pressure gauges.
6. As traction circuit pressure reaches approximately
1800 PSI, directional valve (PD3) should shift. This shift
will allow counterbalance hydraulic flow to be directed to
the traction assist valve (RV2). While maintaining trac-
tion circuit pressure, look at pressure reading on gauge
connected to the counterbalance test port:
GAUGE READING TO BE 650 to 750 PSI.
7. Adjustment of the traction assist valve (RV2) can be
performed as follows:
NOTE: Do not remove the valve from the hydraulic
manifold for adjustment.
A. To increase pressure setting, loosen the locknut
and turn the adjusting screw on the relief valve in a
clockwise direction. A 1/8 turn on the dial will make a
measurable change in pressure (Fig. 45).
B. To decrease pressure setting, loosen the locknut
and turn the adjusting screw on the relief valve in a
counterclockwise direction. A 1/8 turn on the dial will
make a measurable change in pressure (Fig. 45).
C. Recheck pressure and readjust as needed.
Groundsmaster 4500--D/4700--D
2
1. Traction assist manifold (GM 4500- -D shown)
2. Counterbalance test port
1
1. Forward traction port (faces forward)
3
1
1. GM 4500- -D traction assist manifold
2. GM 4700- -D traction assist manifold
3. Traction assist valve (RV2)
Page 4 - - 51
1
Figure 51
Figure 52
3
2
Figure 53
Hydraulic System (Rev. A)