Toro Groundsmaster 4000-D Service Manual page 69

Procedure for Traction Circuit Relief 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.
CAUTION
Move machine to an open area, away from
people and obstructions.
2. Drive machine to an open area, lower cutting decks,
turn the engine off and apply the parking brake.
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 10,000 PSI (700 bar) pressure gauge to
traction circuit test port for function to be checked (Fig.
22 or 23).
4. Start the engine and move throttle to full speed (2870
RPM). Release parking brake. Make sure that trans-
port/4WD switch is in the transport position.
5. Sit on seat, apply brakes fully and slowly depress the
traction pedal in the appropriate direction. While
pushing traction pedal, look at pressure reading on
gauge:
GAUGE READING TO BE:
Forward: 3750 to 4250 PSI (259 bar to 293 bar)
Reverse: 4750 to 5250 PSI (328 to 362 bar)
6. Release traction pedal and stop engine. Record test
results.
7. If traction pressure is too low, inspect traction pump
relief valves (Fig. 24). Clean or replace valves as neces-
sary. These cartridge type valves are factory set, and
are not adjustable. If relief valves are in good condition,
traction pump or wheel motors should be suspected of
wear and inefficiency.
NOTE: Seal leakage across pilot directional valves
PD1 and PD2 in 4WD manifold can also cause low for-
ward traction pressure with reverse pressure meeting
specifications.
8. When testing is completed, disconnect pressure
gauge from test port.
Groundsmaster 4000--D
1. Forward traction port
1. Reverse traction port
RIGHT
2
FRONT
1. Forward relief valve
2. Reverse relief valve
Page 4 - - 35
2
1
Figure 22
2. Left front wheel
2
1
Figure 23
2. Right front wheel
1
Figure 24
3. Traction pump
Hydraulic System
3