Toro Groundsmaster 4500-D Service Manual page 65

Procedure for Traction Circuit Charge 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 onto charge pressure
test port located on rear of filter manifold under right
hand frame rail (Fig. 24 and 25).
4. Start the engine and put throttle at full engine speed
(2800 + 50 RPM) with no load on the hydraulic system.
GAUGE READING TO BE 230 to 300 PSI.
5. If there is no pressure, or pressure is low, check for
restriction in pump intake line. Also, inspect charge relief
valve located in filter manifold and charge check valve
/system relief valve in hydrostat. If necessary, check for
internal damage or worn parts in gear pump.
6. Also, with the pressure gauge still connected to the
charge pressure test port, monitor the gauge reading
while operating the machine in forward and reverse.
Start the engine and put throttle at full engine speed
(2800 + 50 RPM). Apply the brakes and push the trac-
tion pedal forward, then reverse.
GAUGE READING TO BE 230 to 300 PSI.
7. If pressure is good under no load, but drops below
specification when under traction load, the piston (trac-
tion) pump, front wheel motors, and/or rear axle motor
should be suspected of wear and inefficiency. When the
pump and/or traction motor(s) are worn or damaged, the
charge pump is not able to keep up with internal leakage
in traction circuit components.
Groundsmaster 4500--D/4700--D
1
1. Right side frame rail
1. Charge pressure port
Page 4 - - 27
Rev. D
Figure 24
2. Filter manifold
1
2
Figure 25
2. Filter manifold
Hydraulic System (Rev. A)
2