Toro Groundsmaster 4100-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: If steering and lift/lower gear pump section is
worn or damaged, charge, steering and lift circuits will
all be affected.
NOTE: While rotating the steering wheel and raising
the deck 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 deck 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 deck
lowered and off. Make sure engine is off and the parking
brake is engaged. Raise and support seat.
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. Thoroughly clean junction of fitting and hydraulic
hose at the third gear pump section which supplies the
steering and lift/lower circuits (Fig. 47).
4. With the engine off and cutting deck lowered, discon-
nect the hydraulic hose from the 90
gear pump section.
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.
5. Install tester with pressure gauge and flow meter in
series between the fitting and the disconnected hose.
Make sure the flow control valve on the tester is fully
open.
6. After installing tester, start engine and run at idle
speed. Check for hydraulic leakage at tester location
and correct before proceeding with test.
Groundsmaster 4100--D/4110--D
IMPORTANT: The gear pump is a positive displace-
ment type. If pump flow is completely restricted or
stopped, damage to the pump, tester or other com-
ponents could occur.
7. Move throttle so engine is running at high idle speed
(2870 RPM). DO NOT engage the cutting deck.
8. While watching pressure gauge on the 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.
NOTE: If engine speed drops below 2870 RPM, pump
flow will decrease.
9. Open the tester flow control valve and stop the en-
gine. Record test results.
10.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 the gear pump is worn or dama-
ged.
11. When testing is complete, remove tester and recon-
nect hose to pump fitting.
o
fitting in the third
1. Gear pump
2. Fan drive manifold
Page 4 - - 65
GAUGE READING TO BE: Flow approximately 7
GPM (26 LPM) at 1000 PSI (69 bar).
2
4
1
Figure 47
RIGHT
FRONT
3
3. Steering/lift supply hose
o
4. 90
fitting
Hydraulic System