Toro Groundsmaster 4000-D Service Manual page 103

Procedure for Steering and Lift/Lower Gear Pump
Flow Test
NOTE: Output from the steering and lift/lower gear
pump section is equally divided by a proportional valve
to provide flow to the steering circuit and the lift circuit.
The proportional valve is in the fan drive manifold.
NOTE: While rotating the steering wheel and raising
the decks at the same time with the engine running at
high idle speed (2870 RPM), an indication of gear pump
damage may be the steering wheel getting hard to turn
and/or the cutting decks raising very slowly.
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine under load for
approximately ten (10) minutes. Make sure the hydrau-
lic tank is full.
2. Park machine on a level surface with the cutting
decks lowered and off. Make sure engine is off and the
parking brake is applied. Raise and support seat to gain
access to the gear pump.
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. With the engine off and cutting decks lowered, dis-
connect the hydraulic hose from the 90
third gear pump section which supplies the steering and
lift/lower circuits (Fig. 50).
IMPORTANT: Make sure that the oil flow indicator
arrow on the flow gauge is showing that the oil will
flow from the pump section, through the tester and
into the hydraulic hose.
4. Install tester (flow and pressure) in series between
the fitting and the disconnected hose. Make sure the
flow control valve on tester is fully open.
IMPORTANT: The pump is a positive displacement
type. If pump flow is completely restricted or
stopped, damage to the pump, tester or other com-
ponents could occur.
Groundsmaster 4000--D/4010--D
5. Start the engine and move throttle to high idle speed
(2870 RPM). DO NOT engage the cutting decks.
6. While watching pressure gauge on tester, slowly
close flow control valve until 1000 PSI (69 bar) is ob-
tained on gauge. Verify that engine speed continues to
be 2870 RPM.
GAUGE READING TO BE: Flow approximately 7
GPM (26 LPM) at 1000 PSI (69 bar).
NOTE: If engine speed drops below 2870 RPM, pump
flow will decrease.
7. Open flow tester control valve, stop engine and re-
cord test results.
8. If a pressure of 1000 PSI (69 bar) could not be ob-
tained or flow is lower than 6 GPM (23 LPM), check for
restriction in pump intake line. If intake line is not re-
stricted, consider that gear pump section for steering
and lift/lower circuits is worn or damaged.
9. When testing is complete, remove tester and recon-
nect hose to pump fitting.
4
o
fitting in the
1. Gear pump
2. Fan drive manifold
Page 4 - - 65
2
3
1
Figure 50
3. Steering/lift supply hose
o
4. 90 fitting
Hydraulic System